Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Last author,　Corresponding author   Language：Japanese  

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

DOI： 10.2109/jcersj2.23134

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Authorship：Last author,　Corresponding author   Language：English   Publisher：The Ceramic Society of Japan  

Two types of glass particles were immersed in simulated body fluid (SBF) at 37 °C. Silicate glass 45S5 with a trademark name “Bioglass” only formed hydroxyapatite (HAp) near the particle surface, leaving a large amount of silica gel in the interior. The second glass type was borosilicate glass with a composition of the 45S5 glass in which a major part of SiO₂ was replaced with B₂O₃; in the samples from it, glass was completely replaced with HAp inside the particles. We used Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, field-emission scanning electron microscopy, and transmission electron microscopy (TEM) to characterize the microscopic structure of samples. When the 45S5 glass was immersed in SBF, the PO₄³⁻(Q⁰) in glass quickly formed amorphous calcium phosphate (ACP), a precursor of HAp. Ca²⁺ preferentially coordinated with PO₄³⁻(Q⁰) forming ACP [Ca²⁺–PO₄³⁻(Q⁰)], which is considered stable, where the notation Q<i>ⁿ</i> represents the number (<i>n</i>) of the bridging oxygen atoms per PO₄ tetrahedron. The TEM results showed that the columnar crystals of HAp grew along the <i>c</i>-axis. In the borosilicate glass, the reaction is thought to progress to the inside through ion transport into the space where B₂O₃ was eluted.

DOI： 10.2109/jcersj2.23113

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Authorship：Last author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s40831-023-00741-x

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Other Link： https://link.springer.com/article/10.1007/s40831-023-00741-x/fulltext.html

Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Mining and Materials Processing Institute of Japan  

A hand-made apparatus to react copper concentrate (Cc)/pyrite (Py)/silica sand (Ss) mixture was developed for an imitated concentrate burner at laboratory scale. An instantaneous (< 1 s) ignition reaction was macroscopically observed by preheated oxygen gas blowing to Cc/Py/Ss mixture with a Fe/SiO₂ mass ratio of 1.1. SEM-EDS analysis was used to observe microstructure and phase distribution in reacted and water-quenched particles. As for the Cc/Ss samples collected at the point close to the gas blowing spot, 70–80 mass% Cu matte phase and heterogeneous slag phase including large amounts of magnetite (Mag) particles were formed. At the lower part from the gas blowing spot with a distance of 275 mm, 60–65 mass% Cu matte phase was confirmed. The area fraction of Mag particles in the slag phase decreased with increasing Py adding concentration in the mixture sample. Our results suggested the concentration and microscopic distribution of Py in the mixture including Cc contributed to control both Cu concentration in matter phase and Mag particle concentration in slag phase.

DOI： 10.2473/journalofmmij.138.170

CiNii Research

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Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Last author   Language：English  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Mining and Materials Processing Institute of Japan  

DOI： 10.2473/journalofmmij.137.110

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

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Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

DOI： 10.1088/1757-899x/619/1/012036

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Other Link： https://iopscience.iop.org/article/10.1088/1757-899X/619/1/012036

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.optmat.2019.109355

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Language：English  

DOI： 10.1007/s11082-019-2024-4

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY PERIODICALS, INC  

DOI： 10.1111/ijag.13480

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jnoncrysol.2019.119526

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Authorship：Corresponding author   Publishing type：Research paper (international conference proceedings)  

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Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

© 2019 The Ceramic Society of Japan. All rights reserved. Calcium phosphates are essential compounds for the sustenance of life, since, for example, many grains that enable to convert food are necessary for use of the fertilizers made of chemically synthesized crystals. We have demonstrated two alternative dry processes for the conversion of hydroxyapatite to tricalcium phosphate by means of thermodynamically controlled heat and electronically generated heat with pulsed laser light. In addition, the conversion efficiency has been quantitatively determined from the Rietveld analysis for powder X-ray diffractionpatterns of the fired and laser-ablated samples. Both conversion processes recycled animals' bones as the source of calcium phosphate, and in the future, this could compensate for the niche area in the absence of wet process for a phosphorus containing sludge through a sewage treatment.

DOI： 10.2109/jcersj2.18190

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DOI： 10.1111/ijag.13106

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DOI： 10.1007/s40831-019-00211-3

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Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jnoncrysol.2019.02.030

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DOI： 10.2109/jcersj2.18039

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File： 2018.11月_アコヤ貝構成物リサイクル_概説.pdf

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

The effects of composition and structure on stress-induced birefringence were studied for glasses with the nominal molar compositions xZnO–(67-x)SnO–33P2O5. The photoelastic constant (PEC) changes systematically from negative values to positive values when ZnO replaces SnO, and PEC ≈ 0 when x = 18.5 mol%. The zero PEC composition can be predicted from the observed coordination numbers and bond lengths of the Zn-, Sn-, and P-polyhedra using an empirical model from the literature.

DOI： 10.1016/j.jnoncrysol.2018.06.016

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/pssb.201800318

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DOI： 10.1016/j-jnoncry

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

Glasses with nominal molar compositions xZnO–(67-x)SnO–33P2O5 were prepared and their structures were determined by 31P MAS-NMR spectroscopy, HPLC, and by X-ray and neutron diffraction. Compositional dependent changes in the thermal and optical properties described in Part I of this study are attributed to changes in the coordination environments of Sn2+- and Zn2+-ions and their effects on the phosphate anionic network. The 31P MAS-NMR and HPLC data reveal broader distributions of P-tetrahedra in glasses with greater ZnO-contents, due to disproportionation reactions of diphosphate anions in the glass melts to form isolated monophosphate anions and larger triphosphate anions, and due to the loss of some phosphate during glass preparation. The diffraction experiments reveal that Zn2+ prefers tetrahedral coordination, whereas Sn2+ is initially incorporated in isolated, three-coordinated sites that convert to four-coordinated sites with greater ZnO contents. These four-coordinated sites must share corners when incorporated into the glass structure and the transition from glasses dominated by isolated SnO3 pyramids to those with subnetworks of (Sn, Zn)O4 polyhedra occurs near x = 20, and is reflected by breaks in the composition-property trends. The second break in properties occurs near x = 40, and reflects both the dominance of the ZnO4 units in the metal subnetwork, as well an increase in the relative numbers of monophosphate anions in the glass structure.

DOI： 10.1016/j.jnoncrysol.2018.04.017

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.7567/JJAP.57.080310

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

J-GLOBAL

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

Glasses with nominal molar compositions xZnO–(67-x)SnO–33P2O5 were prepared and their thermal and optical properties are reported. Density, glass transition temperature, thermal expansion coefficient, viscosity, and refractive index change systematically when ZnO replaces SnO. Raman and infrared spectroscopies provide information about the phosphate anions that constitute the glass network. The compositional trends in glass properties are explained considering the linkages between Sn- and Zn-polyhedra and these different phosphate anions. Property trends fall into three compositional ranges defined by low ZnO concentration (0 ≤ x ≤ 20, region I), intermediate ZnO concentration (20 &lt
x ≤ 40, II), and large ZnO concentrations (40 &lt
x ≤ 50, III).

DOI： 10.1016/j.jnoncrysol.2018.01.030

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© 2018 The Mining and Materials Processing Institute of Japan. FeO–Fe2O3–P2O5 and BaO–FeO–Fe2O3–P2O5 glasses were immersed in ultrapure water at 120C for 24–168 h. The weight loss of ternary barium iron phosphate glasses immersed for 168 h with a value of < 1.0 × 10−9 kg mm−2 (< 0.03% of initial sample weight) was ten times smaller than that of the binary iron phosphate glass. A reaction layer was formed during immersion tests on the barium iron phosphate glasses. FE-SEM observations indicated the thickness of reaction layer increased with immersion time up to a thickness of 150–230 nm. Weight loss of dissolution samples was suppressed once the reaction layer reached a thickness greater than 150 nm. TEM-EDS analysis with selected-area electron diffraction patterns revealed the reaction layer consisted of 6-line ferrihydrite and non-crystalline phase containing phosphorus with a Fe–O richer and no Ba (< 1 at%) composition, compared to the original glass composition. The dissolution and precipitation process of ionic species with a role of Ba ions for local pH modification is discussed for the formation of the reaction layer.

DOI： 10.2320/matertrans.M-M2017854

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s40831-017-0130-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Glasses in the BaO-SnO-P2O5-B2O3 system were prepared and evaluated in order to formulate preform glasses suitable for the fabrication of fiber cores with a very low photoelastic constant. A first glass system (I: xBaO-(60-x)SnO-40P(2)O(5)) was designed with a constant P2O5 content and various BaO contents (0-40 mol. %). Introduction of 3 mol. % of B2O3 to enhance the glass stability leads to the second glass system (II:x'BaO-(57-x')SnO-40P(2)O(5)-3B(2)O(3)) with 33-38 mol. % BaO. The structure of both systems was investigated by 1D/2D magic-angle spinning nuclear magnetic resonance, Raman, and Fourier transform infrared spectroscopic techniques. P-31 NMR showed the presence of Q(2) and Q(1) units in the first system and correlation B-11/P-31 NMR indicated that boron enters into the network as B(OP)(4) structural units. The photoelastic constant was determined and the stability of the best formulations as well as their refractive index dispersion was established. The drawing temperature and isothermal heating time (without crystal precipitation) parameters were also accurately measured by using experimental time-temperature-transition. Considering that the refractive indices of the core and the cladding materials must match, detailed core and cladding compositions for a fiber enabling single-mode waveguide transmission were proposed. Published by AIP Publishing.

DOI： 10.1063/1.4998957

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The viscosity of gasified and synthesized coal slag melts for homogeneous liquid state was measured in air by rotation cylinder method with the viscosity range of 0.2-15 Pa.s in the temperature range 1300-1650 degrees C. The viscosity decreased monotonically with increasing temperature for all samples. The viscosity of AD slag melt with relatively-high Fe2O3 (similar to 8 mol%) and low SiO2 (similar to 40 mol%) contents rapidly increased with decreasing temperature from 2 Pa.s at 1350 degrees C to similar to 10 Pa.s at 1300 degrees C presumably due to crystallization. The viscosity of gasified coal slag melts increased with increasing contents of Al2O3 and SiO2 and decreased with increasing contents of CaO, MgO, FeO, and Fe2O3. The roles of these main components on melt viscosity are classified into network former (NWF) and modifier (NWM). Two types of amphoteric oxides: Al2O3 and Fe2O3 play different respective roles of NWF and NWM on viscosity for gasified and synthesized slag melts in CaO-MgO-Al2O3-FeO-Fe2O3-SiO2 system. A parameter relating to the total contents of NWF and NWM is proposed to predict the viscosity of slag melts at high temperatures from chemical composition. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2017.03.094

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Authorship：Corresponding author   Language：Japanese   Publisher：ニューガラスフォーラム  

CiNii Books

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Authorship：Corresponding author   Language：English   Publishing type：Part of collection (book)   Publisher：Elsevier Inc.  

Pearl shells, which are yielded as a waste during jewel pearl culture process at Uwajima sea in Ehime prefecture, Japan, are micro-/nanostructured composite materials alternatively consisting of organic and inorganic CaCO3 layers with nanothicknesses. Micro-/nanosized pearl particles are candidates for Ca nutrients and hydroxyapatite (HAp) formation. Iron oxide nanocubes with surfactant are self-assembled into closed packing structures. The integrated structure of thermal-imprinted glass templates with functional nanoparticles becomes a potential candidate for new therapeutic nanostructures. Magnetic Y3Fe5O12 and Fe3O4 particles prepared by either break down or built-up processes were evaluated for thermal coagulation therapy. The dissolution behavior of micrometer-sized pearl powder was also evaluated in artificial stomach acid at 37°C. Future directions of micro-/nanostructured materials are proposed for biomedical applications.

DOI： 10.1016/B978-0-323-46142-9.00004-9

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

Sn-containing silicate glasses with zero photoelastic constant (PEC) can potentially substitute zero-PEC Pb-containing glasses as optical fiber current sensor components based on the Faraday effect. These compounds allow monitoring of the electric power by measuring the electric current in high-voltage conductors operated with a 1550-nm light. The toxicity of Pb in these glasses still remains an important issue. However, replacing Pb in the sensors while minimizing the PEC of the resulting device would represent a significant breakthrough. We report a 43.5SnO-56.5SiO(2) glass in molar% with zero PEC of + 0.01 Chi 10(-12) Pa-1 observed with a wavelength of 632.8 nm. (C) 2017 Optical Society of America

DOI： 10.1364/OME.7.000760

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The relationships between the structure and corrosion resistance of glasses with the nominal compositions xBaO-(100 - x)[yFe(2)O(3)-(1 y)P205], where x = 0,10, 20, and y = 30, 35, 40, are discussed. High performance liquid chromatography was used to characterize the phosphate anions that constitute the glass structure, and Mossbauer spectrometry was used to characterize the fractions and coordination environments of Fe2+ and Fe3+ ions in the glasses. Weight loss measurements in water were recorded and the most durable glasses were those with the smallest average phosphate anion sizes, independent of the relative BaO and Fe2O3 contents. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2017.01.027

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Pb-containing glasses such as the PbO-SiO2 series are useful in optical devices because of their low-photoelastic constants (PECs); however, the toxic Pb component in these glasses is problematic. Transparent ternary ZnO-SnO-P2O5 glasses are potential substitutes for low-PEC Pb-containing glasses, but their thermal behavior is not well understood, which inhibits their ability to be drawn into fibers. Herein, we report the surface crystallization behavior of transparent ternary ZnO-SnO-P2O5 glasses, including those with low-PEC compositions, heated under isothermal conditions to temperatures above their glass-transition temperatures. The crystallization conditions for low-PEC phosphate glasses during their thermal processing into shapes of optical modules were deduced. The crystalline compounds precipitated on the surfaces were investigated via X-ray diffraction analysis, micro-Raman spectroscopy, and microscopic observations. A time-temperature-transformation diagram was constructed on the basis of the thermal stability of the glasses. We expect that this enhanced understanding of the crystallization behavior induced by the reshaping process will enable fabrication of precise polarization control devices with low PECs, such as optical-fiber current sensors, optical lenses, and filters.

DOI： 10.1007/s10853-016-0507-2

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The densities of re-melted coal slag melts were measured in air using Archimedean double-bob method in the temperature range from 1350 to 1600 degrees C. The main components of gasified coal slags are SiO2, Al2O3, CaO, MgO, FeO and Fe2O3. Slags consisting of the main components with systematic composition variations were synthesized and evaluated for comparison. The experimental results of chelate titration analysis revealed that the percentages of Fe3+ in coal and synthesized slag samples were 47-56% and 68-80% of total Fe, respectively. The density decreased linearly with increasing temperature for all melt samples. The density of gasified and synthesized coal slag melts was found to decrease with increasing Al2O3 and SiO2 contents and to increase with increasing Fe2O3 and FeO contents. The molar volume and the coefficient of volume expansion, which were calculated from measured density values, increased monotonically with increasing Al2O3 content for CaO-Al2O3 SiO2 (CAS) synthesized samples with 40 mol% SiO2. The molar volume for CaO-FeO-Fe2O3-SiO2 (CFS) synthesized samples with 60 mol% SiO2 increased with Fe2O3 addition and exhibited discontinuous change at, similar to 7.5 mol% Fe2O3. The coefficient of volume expansion in the same CFS series decreased with increasing Fe2O3 content showing a minimum value at similar to 7 mol% Fe2O3 and increased in higher Fe2O3 content. A composition parameter calculated from chemical composition was proposed to predict the density of coal slag melts. The relationship between measured density and the composition parameter was analyzed. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2016.05.117

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GLASS TECHNOLOGY  

Mixtures of iron phosphate glass granules and BaSO4 powder, a simulated main sludge component, were melted in air using a platinum crucible. The quenched glass samples consisted mainly of oxide constituents, due to the decomposition of BaSO4 during the heating and melting processes. Thermal stability against crystallisation for the glass samples was evaluated using differential thermal analysis, according to the existence of an exothermic crystallisation peak and the temperature difference between the glass transition and onset of crystallisation temperatures. Water durability was determined by the weight loss per unit surface area after immersion in hot water at 120 degrees C for 72 h. Phosphate network species and chemical bonding were characterised by Raman spectroscopy. Glass compositions with the simulated sludge component were optimised in terms of the thermal stability and the water durability, and characterised according to the O/P ratio.

DOI： 10.13036/17533562.57.5.047

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s40831-016-0053-9

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

We report transparent RO-SnO-P2O5 (R = Zn, Ba, Sr) glasses with low photoelastic constant less than similar to 1 B (1 x 10(-1)2 Pa-1) and high refractive index more than similar to 1.65. The BaO or SrO substitution effect of SnO on optical properties is nearly the same as ZnO substitution of the ternary zinc tin-phosphate glass without hazardous oxide. A new series of BaO-SnO-P2O5 glass characterized with a very low photoelastic constant of similar to 0.08 B, high refractive index (similar to 1.66), and better water durability is a candidate for precise polarization control devices such as optical filters and beam splitters. (C) 2015 Optical Society of America

DOI： 10.1364/OL.41.000045

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

The search for an enhanced glass medium to immobilize the sludge at the Fukushima Daiichi Nuclear Power Plant is our main purpose. The iron phosphate glass (IPG) is a potential candidate as we set about assessing it by means of theoretical and experimental investigation. Based on the results of this study, the IPG showed favorable characteristics as a vitrification medium for the sludge.

DOI： 10.1080/00223131.2015.1136579

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

An optical fiber made of zinc tin boro-phosphate glass having a zero photoelastic constant, good water durability, and excluding hazardous elements was drawn from a prepared preform for use in a fiber-type current sensor device. The proposed cladding compositions enable single-mode propagation for a wavelength of 1550 nm, which is estimated from the difference in the refractive index between the core and cladding compositions. The drawing conditions should be controlled since the multiple-component glass is very sensitive to changes in viscosity and crystal precipitation during the heat-treated stretching of the preform. The temperature dependence of viscosity in the core and cladding reveals the feasibility of drawing. (c) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.100307

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Institute of Energy  

Viscosities of molten coal and synthesized slags with systematic composition variations were measured by rotation cylinder method in the temperature range of 1350 and 1650℃ in air. XRF analysis revealed that the main components of the coal slags are SiO_2, Al_2O_3, Fe_2O_3, CaO, and MgO. The roles of the main components on melt viscosity are classified into two types of network former and modifier. Two types of amphoteric oxides in coal slags plays different roles on melt viscosity; Al_2O_3 plays the role of network former, on the contrary, Fe_2O_3 behaves as a modifier. A composition parameter relating to the contents of network former and modifier was proposed to predict the viscosity of molten slag at high temperatures. Appropriate compositions of coal slag for the main components are estimated for the condition of good fluidity with a moderate viscosity of &le; 5 Pa・s at &ge; 1550℃.

CiNii Books

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Institute of Energy  

Correlations between microstructures and melting behaviors of various coal ashes and slags were investigated by using multi-nuclear solid-state nuclear magnetic resonance (NMR), X-ray diffraction, and high-temperature viscometer. Quantitative analyses by NMR showed that the fluidity was influenced by the microstructure. Observed non-Newtonian behaviors even at high temperature for coal ashes and slags having high Si and Al contents were found to be attributed to largely developed network structures of Si and Al tetrahedrons. On the other hand, a fragmentation of the newtwork structures induced by alkaline-earth ions lowered the viscosity. Furthermore, a good correlation between thermal transformations of the microstructure and the melting behaviors was obtained for two kinds of coal ashes and slags haing similar contents of CaO, Fe_2O_3 and SiO_2 + Al_2O_3 but different Si/Al ratio.

CiNii Books

J-GLOBAL

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

We report properties of zero birefringent xZnO-(67-x) SnO-(33-y) P2O5-yB(2)O(3) glasses, within 18.5 &lt;= x &lt;= 22 and y = 0, 3, and 10 mol. %. These compositions of boro-phosphate glasses provide both zero photoelastic constant (PEC) and improved water durability. x = 19 and y = 3 compositions show minimum PEC of -0.002 x 10(-12) Pa-1, which can contribute to candidate material for fiber current sensor devise without lead. The structures of zero photoelastic glasses were investigated by Raman scattering and nuclear magnetic resonance spectroscopies. Compositions of zero PEC glasses are explained by the empirical model proposed by Zwanziger et al. [Chem. Mater. 19, 286-290 (2007)]. (C) 2015 Author(s).

DOI： 10.1063/1.4917347

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Calcium silicate and aluminosilicate glasses with various SiO2 contents (10-76 mol%) were prepared in the wide range of [Al2O3MCaO] molar ratio from 0.10 to 4.00 by conventional melt-quenching method and an aerodynamic levitation device for a part of peraluminus glasses. Variations of glass transition temperature, the coefficient of linear expansion, and ionic packing factor derived from density measurements with [Al2O3]/[CaO] molar ratio were studied. The glass structures of SiO4 three dimensional network, mixed anions of (Si, Al)O-4 tetrahedra, isolated AlO4 and Al-O-Al linkages were evaluated by FT-IR measurements. Compositional dependences of the properties are qualitatively related to the glass structure examined by IR spectroscopy and the proportions of AlOx (x = 4, 5, 6) species evaluated in a previous study by using Al-27 MQ NMR spectroscopy. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2014.12.019

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Effect of B2O3/P2O5 substitution on the properties and structure of the ternary 67SnO-(33-x)P2O5 -xB(2)O(3) composition line (from x = 0-33 mol%) are examined in this contribution. We show that density and glass transition temperature increase while molar volume and thermal expansion coefficient decrease with increasing B2O3 concentration. Density and thermal properties experience an original three-domain evolution with rapid (region I: 0 &lt;= x &lt; 5), substantial (II: 5 &lt;x &lt;= 15), and moderate (III: 15 &lt;x &lt;= 33) increase. In order to explain this unconventional behaviour, the glass structure has been investigated using high magnetic field 1 dimensional P-31 and B-11 MAS-NMR, micro-Raman and infrared spectroscopies. B-11 MAS-NMR experiments allow to (i) monitor the 3- and 4-fold coordinated borate species proportion and (ii) highlight the presence of unreported 4-fold coordinated species in the region (III). Finally, it is shown that substitution of P2O5 by B2O3 induces an alteration of the dimeric phosphate network and formation of mixed anion structure that consists of Q(0) phosphate units, 3- and 4-fold coordinated borate units and their combinations. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matchemphys.2014.11.021

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The structure of tin borophosphate glasses, considered for the development of low temperature sealing glasses or anode materials for Li-batteries, has been analysed at the intermediate length scale by a combination of high field standard and advanced 1D/2D nuclear magnetic resonance techniques. The nature and extent of B/P mixing were analysed using the B-11(P-31) dipolar heteronuclear multiple quantum coherence NMR sequence and the data interpretation allowed (i) detecting the presence and analysing the nature of the B-O-P linkages, (ii) re-interpreting the 1D P-31 spectra and (iii) extracting the proportion of P connected to borate species. Interaction between the different borate species was analysed using the B-11 double quantum-simple quantum experiment to (i) investigate the presence and nature of the B-O-B linkage, (ii) assign the different borate species observed all along the composition line and (iii) monitor the borate network formation. In addition, Sn-119 static NMR was used to investigate the evolution of the chemical environment of the tin polyhedra. Altogether, the set of data allowed determining the structural units constituting the glass network and quantifying the extent of B/P mixing. The structural data were then used to explain the non-linear and unusual evolution of the glass transition temperature.

DOI： 10.1039/c5cp02095f

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

For the first time, a thio-phosphorus oxynitride glass containing nitrogen and sulfur, LiPOSN, has been prepared by a melting process in two steps and its manipulation is possible in air without any decomposition. The anionic substitution of oxygen by sulfur and nitrogen in the phosphate glass structure has been confirmed by 1D(31)P solid state NMR and XPS. The 2D(31)P DQ-SQ experiment indicates that S bearing phosphate groups are integrated into the global phosphate network and do not form clusters. Through the study of the properties of this glass, it was verified a decrease of the glass transition temperature, due to the depolymerization of the phosphate network when lithium sulfide is introduced into the oxynitride glass, along with a pronounced increase of the ionic conductivity, that suggest that this glass can be considered as a new highly conductive and corrosion resistant glass electrolyte. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2014.09.011

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

Red fluorescence lamellae in prismatic layers of Pinctada vulgaris shell were investigated. SEM-EDS, XRD, and TG-DTA were utilized to characterize prismatic layers. We found that prismatic layers are calcitic prismatic (CP) layers with rich organic substances. Excitation spectrum for red fluorescence determined by a spectrophotometer indicates that the fluorescent matter in the organic substances is porphyrin compound derivatives. By using a fluorescence microspectroscope, the cross section of CP layers shows red fluorescence forming lamellar pattern. The lamellar pattern consists of red and black parallel zones with a modulation of emission intensity. Elemental mapping show a correlation of the fluorescence intensity decay with sulphur-rich zones occupying the CP layers in the black zones. (C)2014 Optical Society of America

DOI： 10.1364/OME.4.001813

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The transformation of the Si-Al microstructures of slags, which have similar SiO2 + Al2O3 and CaO contents but different SiO2/Al2O3 ratios, was quantified using multinuclear SS-NMR. Three kinds of Si Q(n) microstructures (Q(2), Q(3), and Q(4)), where n denotes the number of bridging oxygen linked to other Si atoms for each Q(SiO4) unit, and one Al structure (Al (IV)) were present in both slags. The Q(3) percentage in two slags was increased as increase of temperature from 1200 to 1600 degrees C. The transformation of Si-Al microstructures was interpreted by a hypothetic model of cristobalite cluster based on the crystal and Q(n) structure. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jiec.2013.07.015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

We studied structural, optical and vibrational properties of K-doped ZnO nanostructures. X-ray diffraction studies reveal that the prepared particles are hexagonal wurtzite in structure. Increase in lattice parameters and unit cell volume is observed after K doping. Dopant influences on stress, strain of the system are studied using W-H plots. Band gap variation by doping of K is identified from optical absorption studies. Photoluminescence studies have given insight into the enhancement in blue emission observed by K doping along with the near band emission of nano ZnO. From Fourier transform infrared spectral measurements, K-related local vibration mode is observed along with the information related to influence of doping on characteristic vibrational modes of ZnO.

DOI： 10.1007/s00339-013-8139-8

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The thermal stability against crystallisation and the durability in water of barium phosphate glasses including small amounts of B2O3 and/or Al2O3 (≤6 mol%) are characterized by measuring their glass transition and crystallization temperatures and weight loss after immersion testing. The results of Raman and infrared spectroscopy are used to interpret the modification and linkage of phosphate networks with borophosphate, borate and aluminate species. The properties and structural relationships of these glasses is qualitatively discussed.

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

We report the preparation of porous glass films on transparent conductive oxide-coated glass substrates using the phase separation phenomena and the growth behavior of the phase-separated structure. We confirmed that the etched glass films are composed of microscale pores, a three-dimensional porous framework of SiO2-rich phase with widths of about 40-300 nm, and a thin surface layer of about 40-90 nm thick. The SiO2-rich phase grew by diffusion-dominated growth and then viscous flow-dominated growth.

DOI： 10.1007/s10853-013-7618-9

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The thermal properties of ZnO-SnO-P2O5 (ZSP) glasses are evaluated for preparing optical fibres relevant to fibre current-sensor applications. Time-temperature-transformation (TTT) diagrams of ZSP glasses are presented based on x-ray diffraction analysis and microstructural observations. Thermal stability for fibre drawing is discussed along with viscosity data. Selected fabrication conditions, which can minimize microcrystal formation during isothermal heat treatments, are proposed for ZSP glass fibres. © 2013 Publishing Technology.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GLASS TECHNOLOGY  

The thermal properties of ZnO-SnO-P2O5 (ZSP) glasses are evaluated for preparing optical fibres relevant to fibre current-sensor applications. Time-temperature-transformation (TTT) diagrams of ZSP glasses are presented based on x-ray diffraction analysis and microstructural observations. Thermal stability for fibre drawing is discussed along with viscosity data. Selected fabrication conditions, which can minimize microcrystal formation during isothermal heat treatments, are proposed for ZSP glass fibres.

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Authorship：Corresponding author   Language：Japanese   Publisher：The Mining and Materials Processing Institute of Japan  

Glass samples of Na₂O–P₂O₅–SiO₂ containing Nd₂O₃ with <tt>～</tt>0.3 mol% were prepared by melting on a hotfilament and quenching. Absorption spectra of 4f-4f forced-electric dipole transitions of Nd³⁺ were evaluated with a commercial spectrophotometer. Local structures around Nd³⁺ ions were estimated by the shape, peak wavelengths, and absorbance of ⁴I_9/2<tt>→</tt>⁴G_5/2, ²G_7/2 and ⁴I_9/2<tt>→</tt>⁴F_5/2, ²H_9/2 transitions with the interpretation of previous results concerning EXAFS analysis. Absorption spectra indicate that the composition at which Nd³⁺ ions are selectively coordinated by PO₄ tetrahedra is [Na₂O]/[P₂O₅] 2 in a molar ratio for Na₂O–P₂O₅ glasses and [Na₂O]/[P₂O₅] 1 for Na₂O–P₂O₅–SiO₂ glasses. IR spectroscopy results the glasses mainly consist of PO₄ Q² units and P–O–P bonding. Elution tests reveal that Nd constituents, coordinated with PO₄ tetrahedra, with a large fraction of <tt>～</tt>0.9 were dissolved into ultra-pure water at 30ºC for the phosphosilicate glasses with [Na₂O]/[P₂O₅] 1.

DOI： 10.2473/journalofmmij.129.591

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A series of transparent SnO-P2O5 (SP) and SnO-P 2O5-B2O3 (SPB) glasses, with the composition 67SnO-(33-x) P2O5-xB2O3 where x=0, 3, 5, 7 and 10 mol%, were immersed in distilled water at 40 and 70°C for up to 504 hours (3 weeks). Their dissolution behaviour was evaluated by macroscopic inspection, by measurement of weight loss per unit area, changes in the pH of the solution, x-ray diffraction analysis and infrared spectroscopy. The dissolution of Q1 phosphate species and/or BO 3 and BO4 borate units into water for the SP and SPB glasses with ≤7 mol% B2O3 is accompanies crystallization of Sn3(PO4)2. Infrared spectroscopy provides further evidence of the good durability of SPB glass containing 10 mol% B2O3 and reveals the formation of a hydrous layer related to B-O-B linkages on the glass surface. © 2013 Publishing Technology.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Optical Society of American (OSA)  

The unusual dependence of femtosecond laser writing on the light polarization and direction of raster scanning is demonstrated in silica and chalcogenide glasses. Two different mechanisms contributing to the observed anisotropy are identified: the chevron-shaped stress induced by the sample movement and the pulse front tilt of ultrashort light pulse. Control of anisotropies associated with the spatio-temporal asymmetry of an ultrashort pulse beam and scanning geometry is crucial in the ultrafast laser machining of transparent materials. © 2012 Optical Society of America.

DOI： 10.1364/OE.21.003959

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

The great amount of water used for cooling the stricken power reactors at Fukushima Dai-ichi following the earthquake and tsunami of 11 March 2011 has resulted in accumulation of cooling water so-called the remaining water in some buildings.
As the cooling water is subsequently contaminated by fission products (FPs) and some other radioactive substances, it is necessary to decontaminate this 'cooling water' to reduce the volume of liquid radioactive waste and to reuse it again for cooling the affected reactors.
Some methods are applied to remove the radioactive substances from the cooling water. However, after treatments of water, there arises a secondary radioactive waste, the sludge. Steps are now taken to immobilize this sludge.
In this paper, BaSO4, as one of main constituents of the sludge, was chosen as an immobilizing target substance. The appropriate manufacturing condition of glass waste form for loading the sludge (BaSO4) was studied and the chemical durability was evaluated by measuring the dissolution rate. For this experiment, the iron phosphate glass (IPG), which is known to possess a large loading capacity for a variety of chemical substances, was employed as the glass medium.
Based on experimental results, it is evident that BaSO4 can be loaded into the IPG medium when it possesses the appropriate composition and melting temperature. During loading, BaSO4 converted into BaO, acting as a network modifier, which leads to enhanced stability of IPG.

DOI： 10.1115/ICEM2013-96107

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

As the part of investigation for immobilization of the sludge as one of the radioactive wastes arising from the treatment of contaminated water at Fukushima Dai-ichi nuclear power plant, applicability of vitrification method has been evaluated as a candidate technique.
The aim of this study is to evaluate the influence of NaCl as one of the main constituents of sludge, on glass formation and glass properties. Two kinds of iron phosphate glass (IPG) media in the xFe(2)O(3)-(100-x)P2O5, with x=30 and 35 (mol%) were chosen and the glass formation, structure and properties including density, coefficient of thermal expansion, glass transition temperature, onset crystallization temperature and chemical durability of NaCl-loaded IPG were studied. The results are summarized as follows.
Sodium chloride, NaCl could be loaded into IPG medium as Na2O and Cl contents and their loading ratio could be up to 19 and 15 mol%, respectively. Majority of Cl content of raw material NaCl was thought to be volatilized during glass melting. Loading NaCl into IPG induces to depolymerize glass network of phosphate chains, leads to decrease both glass transition and onset crystallization temperatures, and to increase coefficient of thermal expansion. NaCl-loaded IPG indicated good chemical durability in case of using 35Fe(2)O(3)-65P(2)O(5) medium.

DOI： 10.1115/ICEM2013-96108

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

The photoelastic constant (PEC) is evaluated for 15 zinc tin phosphate glasses in a series of xZnO-(67-x)SnO-33P(2)O(5) where x is 0-30 mol. % at 0.5-7 mol. % intervals. The phase retardation of polarized light, passing through a disk sample with applying various uniaxial loads, was measured for PEC determinations by using a frequency stabilized transverse Zeeman He-Ne laser as a polarized light source. The substitution of ZnO for SnO results in the increase of PEC from negative to positive values in the range of -1.43 and +/- 1.45 x 10(-12) Pa-1. The minimum PEC value of 0.04 +/- 0.02 x 10(-12) Pa-1 was experimentally obtained in the 18.5 mol. % ZnO-48.5 mol. % SnO-33 mol. % P2O5 glass. (C) 2012 Optical Society of America

DOI： 10.1364/OL.37.004203

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Correlations among compositions, microstructures, and fluidity properties of three typical Asian coal ashes and their rapidly quenched slags were systematically investigated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and multinuclear solid-state nuclear magnetic resonance (SS-NMR). The viscosities were measured from 1700 degrees C to their solidification temperatures. Different fluidity properties were found because of the presence of the various microstructures. The Datong ash and slag, with the highest viscosity in this study, mainly consisted of Q(4) and Q(3) structures of Si with a high degree of polymerization. The Malinau ash and slag with high iron contents had a Si structure similar to that of the Datong ash; the Q(4) and Q(3). structures indicated that the divalent Fe ions may principally bond as a framework modifier with Al tetrahedrons rather than Si tetrahedrons. In addition, alkaline-earth ions in the Adaro ash and slag segmented the framework to form primary Q(3) and Q(2) structures, resulting in the lowest viscosity.

DOI： 10.1021/ef201771f

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Structural and compositional transitions of Datong coal ash and its CaCO 3 additional effects were carefully examined at a temperature range of 300 to 1 600 °C by using XRD and solid state NMR. The quantitative estimation of amorphous structures of ashes can be successfully obtained through the analyses of solid state NMR spectra. Viscosity of molten ash and its changes with CaCO 3 addition were also evaluated up to 1 700°C by using a rotary type viscometer. Glasses with poor crystalline and amorphous phase were continuously formed through the eutectic reaction of silica above fusing temperature (FT&gt
1 500°C) that caused broadening and shift of 29Si and 27Al peaks in NMR results. With the additional amount of CaCO 3 increasing, the peaks shifted to downfield obviously
the fraction of Si(OAl) 0(OSi) 4 decreased, while that of Si(OAl) 1(OSi) 1 at -84.3×10 -6 increased apparently. These transitions indicated the destruction of large alumina-silicate framework into small segments by the addition of Ca ion. © 2012 The Editorial Office of Journal of Coal Science and Engineering (China) and Springer-Verlag Berlin Heidelberg.

DOI： 10.1007/s12404-012-0114-z

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Mining and Materials Processing Institute of Japan  

The effect of Al<SUB>2</SUB>O<SUB>3</SUB> on glass transition temperature T<SUB>g</SUB> and thermal expansion coefficient α is studied for CaO-Al<SUB>2</SUB>O<SUB>3</SUB>-SiO<SUB>2</SUB> glasses including 45, 50, 55, and 60 mol% SiO<SUB>2</SUB> with a molar ratio of CaO/Al<SUB>2</SUB>O<SUB>3</SUB> > 1. T<SUB>g</SUB> increases and α decreases monotonically with increasing Al<SUB>2</SUB>O<SUB>3</SUB> concentration. The result of infrared spectra suggests the formation of ring-type mixed anions of SiO<SUB>4</SUB> and AlO<SUB>4</SUB> due to Al<SUB>2</SUB>O<SUB>3</SUB> addition. The measured values of α are related to a parameter calculated from the coulomb force between cation and oxide anion based on chemical composition.

DOI： 10.2473/journalofmmij.128.150

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Language：Japanese   Publisher：Atomic Energy Society of Japan  

DOI： 10.11561/aesj.2012f.0.509.0

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Language：Japanese   Publisher：Atomic Energy Society of Japan  

DOI： 10.11561/aesj.2012f.0.508.0

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Minerals, Metals and Materials Society  

Fine zinc concentrates tend to become sticky when roasted in a fluidized-bed reactor. The oxidation of high-purity ZnS powders and ZnS concentrates with different particle sizes were studied in terms of phase changes and particle morphologies. The sample materials were directly oxidized to ZnO in a roasting process performed over 700°C. Zinc oxide particles with diameters less than 0.5 μm formed at 700°C
the particle size increased by grain growth at 900°C. The coarse ZnS concentrate formed the oxysulfate ZnO·2ZnSO4 when roasted at 700°C
the sulfate transformed to ZnO at higher temperature.

DOI： 10.1002/9781118364765.ch19

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Structures and optical properties of selenium-loaded single-crystalline ZSM-5 (z-Se) have been studied. Obtained results are compared with those for bulk Se. Structural measurements using Raman-scattering and X-ray diffraction reveal that Se clusters in the ZSM-5 exist as single chains. Electron-spin resonance (ESR) measurements suggest that the chain has finite lengths of ~5 nm. Optical properties and photoinduced phenomena of z-Se are explored through ESR, absorption (α), and photoluminescence (PL) measurements upon exposure of visible light at room temperature.

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The change of the viscoelastic flow near the imprinting temperature was analyzed by a penetration method with a commercial TMA and the result was compared with thermally-imprinted SnO-P2O5 (SP) and SnO-B2O3-P2O5 (SBP) glass samples by an imprint apparatus. The viscosity of SP glass increases monotonically with increasing SnO content and the specific movement is shown in viscoelastic flow under the optimized thermal imprinting temperature for SP glasses. © 2011 Ceramic Society of Japan.

DOI： 10.1088/1757-899X/18/11/112014

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Effect of R type on absorption and luminescence properties in xMnO-(50 - x)RO-50P(2)O(5) glasses where R = Zn, Mg, Ca, Sr, and Ba with x = 1, 5, and 10 is studied. The (6)A(1) (S) -&gt; T-4(2), E-4 (D) and (6)A(1) (S) -&gt; (4)A(1), E-4 (G) transitions of Mn2+ are observed in absorption spectra. The broad emission bands assigned to the T-4(1) (G) -&gt; (6)A(1) (S) transition of Mn2+ are obtained with a peak appeared in the wavelength region of 610-630 nm. The emission peak wavelength, intensity, and quantum yield vary systematically with radius of R ion and Mn concentration. The compositional dependence of the emission properties of Mn2+ in the metaphosphate glasses is interpreted from the point of the local environment around Mn2+ ions. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.optmat.2009.08.001

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GLASS TECHNOLOGY  

The effect of B2O3 additions on the sintering behaviour of BaO-P2O5-B2O3 (BPB) glass powders has been studied. The sintering temperature and time were optimised for the densification of BPB powder compacts. The factors affecting the optical transmittance in the visible region for BPB sintered compacts arc discussed in terms Of microstructure.

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The effect Of B2O3 additions on the sintering behaviour Of BaO-P2O5-B2O3 (BPB) glass powders has been studied. The sintering temperature and time were optimised for the densification of BPB powder compacts. The factors affecting the optical transmittance in the visible region for BPB sintered compacts are discussed in terms of microstructure.

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Thermal imprinting conditions of low-softening tin phosphate glass with a composition of 67 tool % SnO-33 mol % P2O5 were investigated using three processing parameters of temperature, imprinting pressure, and holding time. Fabrication conditions of a micro square grid (SG) pattern with a similar depth or silica mold (similar to 120 nm) were optimized. AFM observations confirmed that the 700 nm x 700 nm SG pattern with similar to 120 nm depth could be formed with good reproducibility. (C)2009 The Ceramic society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.117.783

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GLASS TECHNOLOGY  

Binary zinc phosphate glasses show anamalous behaviour in that thermal expansion coefficient and the glass transition temperature exhibit a minimum value in the range 55 &lt;= ZnO &lt;= 60 mol%. According to Raman and infrared spectroscopy, Q(2) phosphate chains, Q(1) chain terminators and Q(1) dimer units coexist in this range. The variation of thermal properties With ZnO concentration is discussed in terms of network structure, chemical bonding and microheterogeneity.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：TRANS TECH PUBLICATIONS LTD  

Nanosized Y(2)O(3):Eu(3+) crystalline powders with average particle sizes around 100 nm, measured by field-emission scanning electron microscopy (FE-SEM), have been synthesized by a polymerized precursor method using carboxymethyl cellulose (CMC). The nanocrystalline phosphors exhibit intense photoluminescence (PL) and cathodoluminescence (CL) around 612 nm, being attributed to the (5)D(0)(-7)F(2) transition of Eu(3+). Electroluminescence (EL) properties of the nanophosphors in the form of thick films were investigated, and emission of red light with maximum intensity at 612 nm (corresponding to x = 0.57 and y = 0.32 in the CIE chromaticity diagram) was observed under high ac field at 1 kHz. The obtained results suggest a possibility that Y(2)O(3):Eu(3+) nanopowders can be used as a red-emitting phosphor for EL devices.

DOI： 10.4028/0-87849-359-x.123

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：TRANS TECH PUBLICATIONS LTD  

We investigated epitaxial assembly in aggregates of CaTiO(3) nanoparticles, which were synthesized under a hydrothermal condition at 150 degrees C using water/ethanol solvent, by transmission electron microscopy analysis combined with a three-dimensional tomography technique. The obtained results indicate that epitaxial assembly is involved in the crystal growth of CaTiO(3) nanoparticles, and that in aggregates of CaTiO(3) nanoparticles epitaxial assembly occur on their {101} planes.

DOI： 10.4028/0-87849-359-x.127

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We investigated epitaxial assembly in aggregates of BaTiO3 and CaTiO3 nanocrystals, which were synthesized under a hydrothermal condition at 15°C using distilled water-ethanol solvent, by transmission electron microscopy analysis. The volume ratio of distilled water-ethanol used as the solvent gives a significant influence on the crystal growth of the nanocrystals. The obtained results indicate that epitaxial assembly is surely involved in the crystal growth of BaTiO3 and CaTiO3 nanocrystals under the present thermal condition. © 2008 Materials Research Society.

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Mining and Materials Processing Institute of Japan  

A new series of chalcogenide glasses in the Cu<SUB>2</SUB>S-Sb<SUB>2</SUB>S<SUB>3</SUB> system was prepared by a conventional melt-quenching method. The glassy nature of prepared compositions was proved using X-ray diffraction analysis. The homogeneity and microstructure were evaluated using FE-SEM. Physical properties such as glass transition temperature, crystallization temperature, density, optical transmission and electrical resistivity were measured. The results show that the Cu-Sb-S glasses form in the composition region of 21.5 and 24.5 mol% Cu<SUB>2</SUB>S. The glass transition temperature is 185°C and the optical transmission window is lying between 0.9 and 15 μm for the representative 22.5Cu<SUB>2</SUB>S - 77.5Sb<SUB>2</SUB>S<SUB>3</SUB> glass sample. The result of electric resistivity indicates that the change of electric resistivity is about 3 orders by the crystallization of glass.

DOI： 10.2473/journalofmmij.124.644

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

The photoelastic constants (PECs) of transparent SnO-P2O5 (SP) glasses with 52-72 mol% SnO were determined using a frequency stabilized transverse Zeeman He-Ne laser (STZL) at 633 nm. The SIR glass samples were melted at 950 degrees C in carbon crucibles and at 1050 degrees C in alumina crucibles. The melting conditions affect the values of glass transition temperature and OH content but have almost no effect on PEC. The PEC varies monotonically with increasing SnO concentration from -0.73 to -1.98 x 10(-12) Pa-1.

DOI： 10.2109/jcersj2.116.1100

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Binary SnO-P2O5 (SP) glasses with 52-72 SnO mol% were examined. Glass transition temperature, density, refractive index and absorption edge were studied for transparent SP glasses. The structure of SP glasses was evaluated by FT/IR and Raman spectroscopy. The water durability was investigated by weight loss and Raman spectroscopy for SP glass samples immersed in distilled water at 30-70 degrees C. Raman spectra indicated in the immersion test that Q(1) units form and Q(2) units decrease as a result of water attack upon the phosphate chains with increasing immersion time in 62SnO center dot 38P(2)O(5) glass and no structural change was observed in 72SnO center dot 28P(2)O(5) glass. The relationship between the properties and glass structure with chemical bonding is discussed. (C) 2008 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.116.915

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

For micro/nanoimprinting of glass, the appropriate combination of glass and mold material was clarified by an adhesion test using chemical vapor deposition (CVD) diamond, silicon, glassy carbon and sintered nitride ceramics as the mold material, and Pyrex, TEMPAX and BK7 as the glass material. The result of the adhesion test shows that CVD diamond is suitable for imprinting with a wide variety of glass materials under various temperature conditions. The method of fabricating the CVD diamond mold using focused ion beam (FIB) was examined, and it was clarified that the grain boundary of CVD diamond has little effect on the surface condition. Glass micro/nanoimprinting was performed using the CVD diamond mold. The effect of the molding conditions, such as the molding temperature and mold-release temperature, on the height of glass transcription was clarified. The effects of pattern size and shape were also investigated. On the basis of the results, a method of selecting the molding conditions to obtain the desired transcript height was developed. In this research, the entire flow of glass micro/nanoimprinting, including mold material selection, the mold fabrication process and molding process, was proposed experimentally, and the selection method of the molding conditions was shown.

DOI： 10.1088/0960-1317/18/6/065013

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

In this paper, we report the optical and ultrafast nonlinear optical properties of Yb(3+) doped sodium borate and bismuthate glasses. The glasses have been prepared through the melt quench technique. Optical absorption measurements show compositional dependent absorption spectrum of Yb(3+), which is due to the higher crystal field induced by Bi(3+) ions. Local structure of the glasses has been identified by using Fourier transform infrared and Raman studies. From open aperture z-scan measurements done by using 100 fs laser pulses, the ultrafast optical nonlinearity in these materials is calculated at the nonresonant excitation wavelength of 800 nm. The measured three-photon absorption originates from the glass host, with contributions from the nonbridging oxygens and the nonlinear electronic polarization of the Bi(3+) ions. (C) 2008 American Institute of Physics.

DOI： 10.1063/1.2931029

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

Thermal imprinting of transparent tin phosphate glass was performed at 250 degrees C using a fine-patterned silica mold. The glass sample was prepared by a conventional melt-quenching method and polished with a roughness of &lt;= 10 nm for imprinting experiments. The imprinting temperature is optimized based on experimental viscosity data. Scanning electron microscope and atomic force microscope observations revealed that a square grid pattern has a surface roughness of &lt;= 10 nm and 5 mu m X 5 mu m squares with similar to 1 mu m intervals and 90- 100 nm depth. Diffraction spots due to the micropattern are demonstrated by illuminating He-Ne laser light. (C) 2007 Optical Society of America.

DOI： 10.1364/OL.32.002750

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL PUBLISHING  

The photoluminescence of Mg-doped BaTiO3:Pr3+ (Pr3+: 0.1 mol%) ceramics was investigated by changing the doping concentration of Mg and the sintering temperature. The results indicated that the intensity of red emission due to the D-1(2)-&gt; H-3(4) transition of Pr3+ exhibited significant dependence on both the Mg doping content and the sintering temperature; the strongest red emission intensity was observed for 2.0 mol% Mg-doped ceramics sintered at 1050 degrees C. An interpretation of the results obtained was made in terms of the changes in the crystal structure and microstructure of the ceramics.

DOI： 10.1111/j.1551-2916.2007.01811.x

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GLASS TECHNOLOGY  

Viscosity in the range of 10(7) and 10(11) Pas was measured by a penetration method for barium phosphate and borophosphate glass melts in a series of xB(2)O(3)-(100-x)Ba(PO3)(2) where x=0-12 mol%. The viscosity at a certain temperature increases with increasing B(2)O(0)3 concentration. The variation of viscosity with B2O3 concentration is qualitatively related to glass structure reported in previous studies. The immersion test into distilled water for glass plates reveals that B2O3 addition degrades water durability. The microstructure observation reveals the precipitation of many nano-sized particles at the immersed surface of a barium borophosphate glass. No spectral change of Nd3+ absorption was observed in between binary barium phosphate and ternary barium boroposphate glasses due to the site selectivity of Nd3+ ions with PO, networks.

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

CuO-doped barium borophosphate glasses in a series of xCuO-(45 - x)BaO-10B(2)O(3)-45P(2)O(5) in molar ratio with x = 0-15 mol% were prepared by a melt-quenching technique. All the glasses had excellent thermal stability against crystallization. Glass transition temperature, thermal expansion coefficient and molar volume decrease with increasing CuO concentration. The linear relationship between the absorption coefficient and CuO concentration exists for a peak wavelength in the transitions of (2)A1(g) -&gt; B-2(1,) B-2(2g) -&gt; B-2(1g) E-2(g) B-2(1g). The relationship between the properties and glass structure evaluated by Raman spectroscopy is discussed. (C) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.09.044

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Colorless, transparent SnO-P2O5 (SP) glasses with 60-70 mol% SnO compositions were prepared by melting at 880-1000 degrees C in Ar atmosphere using commercial SnO and P2O5 powders as raw materials and vitreous carbon crucibles. SP glasses are characterized by glass transition temperature, onset of crystallization, thermal expansion coefficient and weight loss after immersion test. The viscosity of 67SnO-33P(2)O(5) glass was measured by a penetration method in the range of 10(7.9)-10(10.5) Pa s at 267-290 degrees C. The results of optical properties show that the transparent SP glasses have high refractive indexes over 1.75 and high transmission over 80% in the visible and IR region of 380 and 2700 ran. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jpcs.2007.01.012

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：TRANS TECH PUBLICATIONS LTD  

An investigation has been made on the state of barium titanate (BaTiO3; BTO, hereafter) nanoparticles of 10-15 nm in diameter dispersed in various suspension media, such as 2-methoxyethanol (ethylene glycol monomethyl ether: EGMME) with and without acetylacetone (Acac), ethanol, and isopropanol. The state of the nanoparticles dispersed in these suspension media is deduced from the behavior pattern of their optical transmittance (T), in the wavelength (A) range of 300-900 nm; the concentration (c) of BTO nanoparticles in the suspensions was varied from 0.01 to 0.25 mol/L. T-c plots obtained for EGMME+Acac and EGMME suspensions at various wavelengths indicate that BTO nanoparticles take two and three different states in the suspensions, respectively, from mono-dispersed to agglomerated states with increasing c.

DOI： 10.4028/0-87849-449-9.51

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Bulk binary ZnO-P2O5 glasses with 50-70 mol% ZnO were immersed in distilled water at 30-90 degrees C for up to 72 h. The immersed samples were characterized by weight loss, the change in solution pH, X-ray diffraction (XRD) analysis, scanning electron microscopy and Raman spectroscopy. Weight loss decreased with ZnO concentration for all immersion temperatures. Dissolution behavior was classified into two types in terms of weight loss and macroscopic appearance. Type I was primarily recognized in 50-60 mol% ZnO glasses. In type I, the weight loss for 72 h was relatively large (&gt; 1.0 x 10(-7) kg mm(-2), &gt; 10% of initial sample weight). Raman spectra of the type I glasses indicated that the depolymerization of phosphate glass network occurred during the dissolution process. Crystalline Zn2P2O7-3H(2)O was precipitated in the water solution after immersion. Type II dissolution behavior was recognized in the 65 and 70 mol% ZnO glasses except for the 65ZnO-35P(2)O(5) glass immersed at 90 degrees C. In the type II behavior, the weight loss for 72 h was relatively-small (&lt; 1.0 x 10(-8) kg mm(-2), &lt; 1% of initial sample weight). The microstructure of the type II glass indicated selective dissolution. The dissolution process of the type II glass is discussed. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.04.002

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The relationship between Ag photodoping behavior and glass structure has been studied using various sulfide bulk glasses. The transmission measurement revealed that the photodoping rate increased with an increase of S concentration in Ge-S glasses and GeS2-SbS2 glasses, while the disappearance of Ag film was not be observed in Ge40S60 and Ga2S3-based glasses, which contain modifier ions. The correlation between photodoping rate and S-S bond content in a host glass was confirmed. From the point of view of the behavior of Ag photodoping, sulfide glasses were classified into two groups: (1) a covalent glasses containing S-S bonds and (2) an ionic glasses containing modified ions. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.03.047

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IR transmitting glass-ceramics were prepared by isothermal treatments of La2O3-Ga2S3 glasses. The glass-ceramics were characterized by crystalline phases, microstructure, Vickers hardness and mid (3-5 mu m) IR transmittance. The Nd2S3-doped La2O3-Ga2S3 glass-ceramics consisting of a large numbers of (LaO)(4)Ga1.72S4.58, alpha-(LaO)GaS2 and alpha-Ga2S3 crystals with &lt; 1 mu m in size exhibit a high hardness of 5.3 GPa and a mid IR transparency of &gt; 60%. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.02.063

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Variations in glass transition temperature, onset of crystallization, thermal expansion coefficient, density and molar volume with B2O3 concentration were studied in a series of xB(2)O(3)-(100 - x)Ba(PO3)(2) glasses with 0-10 mol% B2O3. DTA analysis and isothermal treatments for powdered glass samples reveal that &gt;= 7.5 mol% B2O3 addition suppresses surface crystallization during softening process. Raman spectroscopy suggests that the properties are related to the glass structure Consisting Of PO4 Q(2) units with diborate and PO4-BO4 groups. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2005.11.066

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL PUBLISHING  

The glass transition temperature increases and the thermal expansion coefficient and density decrease with increasing B2O3 concentration in a series of (100-x)(50BaO-50P(2)O(5))-xB(2)O(3) where x = 0-10 mol% for bulk samples. According to Raman spectroscopy, the bulk BaO-P2O5-B2O3 (BaP-B) glasses consist of metaphosphate Q(2) units with ring-type metaborate, diborate, and PO4-BO4 groups. X-ray photoelectron spectroscopy results reveal qualitatively that P-O-B bonds are formed at the surface of BaP-B glass samples ground in laboratory air over 6 mol% B2O3 only. The P-O-B bonds are related to the suppression of the crystallization of powdered BaP-B glasses with &gt; 6 mol% B2O3 during differential thermal analysis.

DOI： 10.1111/j.1551-2916.2005.00656.x

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It is observed that writing by femtosecond laser from left to right can be different from writing in the opposite direction. Structures with broken mirror symmetry in chalcogenide glass are discovered. Chiral patterns are demonstrated. © 2006 Optical Society of America.

DOI： 10.1109/CLEO.2006.4627904

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Authorship：Corresponding author   Language：Japanese   Publisher：The Mining and Materials Processing Institute of Japan  

The characteristic temperatures and structure of BaS-Ga<SUB>2</SUB>S<SUB>3</SUB>-GeS<SUB>2</SUB> (BGGS) glasses in a series of (100-x)[65BaS-35Ga<SUB>2</SUB>S<SUB>3</SUB>]-xGeS<SUB>2</SUB> in molar ratio are studied. Glass samples were prepared by a melt quenching method using vitreous carbon crucibles in an inert atmosphere and using vacuumed silica ampoules. Variations in glass transition temperature T<SUB>g</SUB> and onset of crystallization, T<SUB>x</SUB>, with GeS<SUB>2</SUB> concentration are evaluated. The addition of GeS<SUB>2</SUB> enhances the thermal stability evaluated by the temperature difference of T<SUB>x</SUB>-T<SUB>g</SUB>. Raman spectroscopy suggests that mixed-anion networks of GaS<SUB>4</SUB> and GeS<SUB>4</SUB> with the possibility of GeO<SUB>2</SUB> quartz structure for an impurity are formed, which contributes to a good thermal stability of these glasses with T<SUB>x</SUB>-T<SUB>g</SUB> >200°C. The BGGS glass fiber with an optimized composition could be continuously formed.

DOI： 10.2473/shigentosozai.121.260

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This article reviews the fabrication and properties of sulfide glasses and thin films consisting of non-toxic elements: alkaline-earth, rare-earth, germanium and gallium sulfides for optical applications. Refractive indexes, transmission and the fluorescence property of rare-earth ions in sulfide glasses are presented. Factors affecting rare-earth solubility in sulfide glasses are summarized. Thermally-stable BaS-Ga2S3-GeS2 glasses for optical fibers and Nd3+-doped transparent Ga-La-S-O glass-ceramics are described as new optical materials. Sm-doped SrS-Ga 2S3 non-crystalline and nano-crystalline metallic SmS films were irradiated by focused femtosecond laser pulses and new photoinduced phenomena are introduced.

DOI： 10.2109/jcersj.113.37

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Authorship：Corresponding author   Language：Japanese   Publisher：The Mining and Materials Processing Institute of Japan  

Impurity bands in the infrared transmission spectra of Ge-S binary glasses are evaluated. Glass samples with various S concentrations were prepared by ordinary melt-quenching process using Ge and S raw materials and vacuumed fused quartz ampoules as containers. The infrared absorption bands of S-H, Si-O and Ge-O are observed in glasses with Ge-excess compositions over 66.7 at%S (GeS&lt;sub&gt;2&lt;/sub&gt;). In S-excess glasses from 66.7 at%S, the bands due to CS&lt;sub&gt;2&lt;/sub&gt; and S-S bonds are additionally observed. All glasses have infrared transmission up to ∼ 10μm and the absorption edge is determined by the Ge-O impurity band. Possible origins of various impurities are qualititatively discussed.

DOI： 10.2473/shigentosozai.120.607

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

The effect of B2O3 addition on the thermal stability of BaO-P2O5 glasses is studied by differential thermal analysis (DTA), X-ray diffraction (XRD) analysis, scanning electron microscopy, and micro-Raman spectroscopy. The difference between glass-transition and onset-crystallization temperatures increases monotonically with increasing B2O3 concentration. The DTA result reveals that no exothermic peak due to surface crystallization exists in the BaO-P2O5 glass doped with 3 mol% B2O3. A single-mode BaO-P2O5-B2O3 glass fiber could be fabricated by a rod-in-tube technique. The modification of glass structure due to B2O3 addition is qualitatively discussed.

DOI： 10.1111/j.1551-2916.2004.00408.x

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Authorship：Corresponding author   Language：Japanese   Publisher：The Mining and Materials Processing Institute of Japan  

Dense CaS ceramics were prepared by liquid-phase sintering with Ga&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt; additives (0 ∼ 1.0 mol%). A relative density of 96.2% was achieved by the sintering of CaS samples with 0.5mol% Ga&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt;, fired at 1573K for 6h in Ar flow. Sintering process was investigated with scanning electron microscopy observations and linear shrinkage measurements. The sintering process of Ga&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt;-doped CaS was found to be followed by 3 steps: (1) the rearrangement of CaS particles by CaS-Ga&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt; liquid, (2) the dissolution of CaS particles and the precipitation of CaS grains due to diffusion-controlled process and (3) the growth of precipitated CaS grains. X-ray diffraction and microstructural analyses with an energy dispersive X-ray fluorescence spectrometer revealed that sintered CaS has mainly CaS phase and CaS-Ga&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt; liquid segregated around grain boundaries. The thermal expansion coefficient of sintered CaS was 19.1 × 10&lt;sup&gt;-6&lt;/sup&gt;/K in the range room temperature to 1273K. It was suggested that ceramic materials with similar thermal expansion coefficients are appropriate for the substrate of CaS based thin film electroluminescence.

DOI： 10.2473/shigentosozai.119.755

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Nd solubility is evaluated in SrS- and BaS-Ga2S3 glasses using a series of absorption measurements. The result reveals that Nd up to 2-3 mol% can be dissolved in these glasses. Rare-earth solubility in sulfide glasses is discussed in terms of the ionicity of chemical bonds. Raman spectroscopy suggests that Nd ions play a role of modifiers to the networks of GaS4 tetrahedra in a similar manner of the alkaline-earth ions. The limitation of Nd solubility is related to glass-forming ability during the cooling process of alkaline-earth gallium sulfide melts.

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Sb-S binary glass samples with a batch composition of Sb33.3S66.7 could be obtained by a melt-quenching method using a vacuum-sealed silica ampoule. The glass transition temperature of Sb33.3S66.7 glass was 163degreesC. Two series of Ge-Sb-S ternary glasses, namely GeS2-SbS1.5 and GeS2-SbS2 were also prepared. The Ge-Sb-S glasses at 20-40 mol% SbS2 possess relatively-high thermal stability with the difference between glass transition and onset crystallization temperatures over 200degreesC. The compositional dependence of molar volume calculated from measured density was evaluated for Ge-Sb-S glass samples. Raman spectroscopy revealed that Ge-Sb-S glasses consist mainly of GeS4 tetrahedra and SbS3 pyramids and the SbS2 glass is composed of SbS3 pyramids. Additionally Ge-Sb-S glasses at 20-50 mol% SbS2 in a series of GeS2-SbS2 contain S-S bonds.

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Glass-ceramic composites consisting of 10SrO . 50ZnO . 40P(2)O(5) (SZP) glass and Al2O3 with various particle sizes and specific surface areas were fabricated for the barrier-rib of plasma display panel. The variations of density, microstructure, bending strength and thermal expansion coefficient with Al2O3 contents were studied for SZP/Al2O3 composites. The positively or negatively charged surface state of SZP and Al2O3 particles was estimated from the pH of the aqueous suspensions prepared using the mixture of SZP glass or Al2O3 particles with 10 vol% and distilled water with pH 7 without pH adjustment. The combination of SZP glass and Al2O3 raw materials with similar charged surface state provides a dense SZP/Al2O3 sintered composite with a relatively-high bending strength and with a homogeneous microstructure.

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

The photo-elastic constants (PEC) of BaO-P2O5 glasses with 50-57 mol%BaO were determined at 633 nm using a frequency stabilized transverse Zeeman Laser. Measured PEC was found to vary from 0.15 to 0.63 x 10(-12) Pa-1, depending on composition. The concentration effects of OH, Al2O3 and BaO on PEC are studied. PEC increases with increasing Al2O3 concentration for metaphosphate glasses with BaO/P2O5=1. On the other hand, PEC decreases monotonically with increasing BaO concentration. An empirical equation to predict PEC from glass composition is proposed. The correlation between PEC and glass structure, as evaluated by Raman spectroscopy is qualitatively discussed.

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Authorship：Corresponding author   Language：Japanese   Publisher：公益社団法人日本セラミックス協会  

The photo-elastic constants (PEC) of BaO-P_20_5 glasses with 50-57 mol% BaO were determined at 633 nm using a frequency stabilized transverse Zeeman laser. Measured PEC was found to vary from 0.15 to 0.63×10^&lt;-12&gt; Pa^&lt;-1&gt;, depending on composition. The concentration effects of OH, Al_2O_3 and BaO on PEC are studied. PEC increases with increasing Al_2O_3 concentration for metaphosphate glasses with BaO/P_20_5 = 1. On the other hand, PEC decreases monotonically with increasing BaO concentration. An empirical equation to predict PEC from glass composition is proposed. The correlation between PEC and glass structure, as evaluated by Raman spectroscopy is qualitatively discussed.

DOI： 10.2109/jcersj.111.426

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Metallic SmS thin films with 100-2000 nm in thickness were prepared by rf magnetron sputtering. The metallic- to semiconductor-phase transition was induced by a regeneratively amplified mode-locked Ti:sapphire laser. The shifts of the (200) peak due to the phase transition were observed by grazing incidence x-ray diffraction (GIXD) analysis. This phase transition was accompanied by the significant reflectance change of the thin films up to 45% in the near-infrared region. The depth of the phase transition layer from the surface of the film irradiated by a femtosecond laser pulse was estimated similar to200 nm from the depth profile of GIXD. (C) 2003 American Institute of Physics.

DOI： 10.1063/1.1577824

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Microlens formation, as induced by single shot of a femtosecond laser pulse, was observed in Sm-doped non-crystalline SrS-Ga2S3 thin films. The existence of Sm2+ could be related to the photoinduced deformation of the thin films. The confocal scanning laser microscopy observations revealed that detachment in the thin films occurred locally at the center part of the irradiated area.

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Gallium sulfide glasses were prepared in the RS-Ga2S3 (R = Ca, Sr, Ba) systems. Respective glass forming regions are 67.5-70.0 mol% CaS, 63.8-68.8 mol% SrS and 60.0-73.8 mol% BaS. Transmission spectra in the visible region, refractive index and glass transition and onset crystallization temperatures were measured for representative compositions of SrS- and BaS-Ga2S3 transparent glasses. Raman spectroscopy reveals that RS-Ga2S3 glasses consist of the network of GeS4 tetrahedra due to the RS addition. The compositional dependence of molar volume indicates a plateau region at 65-70 mol% RS in SrS- and BaS-Ga2S3 glasses. The morphology of sulfur complex anions in RS-Ga2S3 glass melts is discussed using the sulfur-to-gallium ratio as a variable parameter. The combined results suggest that well-developed glass networks are formed near 66.7 mol% RS (S/Ga = 2.5) in the SrS- and BaS-Ga2S3 systems.

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The solubility of Dy3+ ions in binary Ge-S glasses is studied. A mixture of Dy2S3, Ge and S raw materials in a silica ampoule was sealed under vacuum with 1-2 X 10(4) Pa, melted at 1000degreesC for 20 h with a slow rotation rate of &lt; 1 rpm and then quenched to room temperature to for form a glass. The solubility is evaluated by naked eye, optical microscopy and absorption measurements in glass samples. A linear relation between absorption coefficient and Dy2S3 concentration is obtained for the H-6(15/2)--&gt;H-6(9/2), F-6(11/2) transition in the dissolved glasses. The dissolved concentration of Dy2S3 increases with decreasing S concentration in the Ge-excess compositions under 66.7 mol% S. A solubility model is proposed based on GeS2-like clusters existing in Ge-S glass melts. The dissolved concentration of Dy2S3 is at least 5 mass% (similar to4 x 1026 Dy/m(3)) at 60-62 mol% S (38-40 mol% Ge). This relatively-high solubility is related to the existence of Ge2+ modifier ion's as discussed in our previous study.

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

The photo-elastic constants (PEC) of BaO-P2O5 glasses with 50-57 mol%BaO were determined at 633 nm using a frequency stabilized transverse Zeeman laser. Measured PEC was found to vary from 0.15 to 0.63 × 10-12 Pa-1, depending on composition. The concentration effects of OH, Al2O3 and BaO on PEC are studied. PEC increases with increasing Al2O3 concentration for metaphosphate glasses with BaO/P2O5 = 1. On the other hand, PEC decreases monotonically with increasing BaO concentration. An empirical equation to predict PEC from glass composition is proposed. The correlation between PEC and glass structure, as evaluated by Raman spectroscopy is qualitatively discussed.

DOI： 10.2109/jcersj.111.426

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

Sb-S binary glass samples with a batch composition of Sb 33.3S66.7 could be obtained by a melt-quenching method using a vacuum-sealed silica ampoule. The glass transition temperature of Sb33.3S66.7 glass was 163°C. Two series of Ge-Sb-S ternary glasses, namely GeS2-SbS1.5 and GeS 2-SbS2 were also prepared. The Ge-Sb-S glasses at 20-40 mol% SbS2 possess relatively-high thermal stability with the difference between glass transition and onset crystallization temperatures over 200°C. The compositional dependence of molar volume calculated from measured density was evaluated for Ge-Sb-S glass samples. Raman spectroscopy revealed that Ge-Sb-S glasses consist mainly of GeS4 tetrahedra and SbS3 pyramids and the SbS2 glass is composed of SbS 3 pyramids. Additionally Ge-Sb-S glasses at 20-50 mol% SbS 2 in a series of GeS2-SbS2 contain S-S bonds.

DOI： 10.2109/jcersj.111.572

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

Glass-ceramic composites consisting of 10SrO·50ZnO·40P2O5 (SZP) glass and Al2O3 with various particle sizes and specific surface areas were fabricated for the barrier-rib of plasma display panel. The variations of density, microstructure, bending strength and thermal expansion coefficient with Al2O3 contents were studied for SZP/Al2O3 composites. The positively or negatively charged surface state of SZP and Al2O3 particles was estimated from the pH of the aqueous suspensions prepared using the mixture of SZP glass or Al2O3 particles with 10 vol% and distilled water with pH 7 without pH adjustment. The combination of SZP glass and Al2O3 raw materials with similar charged surface state provides a dense SZP/Al2O3 sintered composite with a relatively-high bending strength and with a homogeneous microstructure.

DOI： 10.2109/jcersj.111.497

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Society of Japan  

Nd solubility is evaluated in SrS- and BaS-Ga2S3 glasses using a series of absorption measurements. The result reveals that Nd up to 2-3 mol% can be dissolved in these glasses. Rare-earth solubility in sulfide glasses is discussed in terms of the ionicity of chemical bonds. Raman spectroscopy suggests that Nd ions play a role of modifiers to the networks of GaS4 tetrahedra in a similar manner of the alkaline-earth ions. The limitation of Nd solubility is related to glass-forming ability during the cooling process of alkaline-earth gallium sulfide melts.

DOI： 10.2109/jcersj.111.755

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Microlens formation, as induced by single shot of a femtosecond laser pulse, was observed in Sm-doped non-crystalline SrS-Ga2S3 thin films. The existence of Sm2+ could be related to the photoinduced deformation of the thin films. The confocal scanning laser microscopy observations revealed that detachment in the thin films occurred locally at the center part of the irradiated area.

DOI： 10.2109/jcersj.111.291

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Gallium sulfide glasses were prepared in the RS-Ga2S3 (R = Ca, Sr, Ba) systems. Respective glass forming regions are 67.5-70.0 mol% CaS, 63.8-68.8 mol% SrS and 60.0-73.8 mol% BaS. Transmission spectra in the visible region, refractive index and glass transition and onset crystallization temperatures were measured for representative compositions of SrS- and BaS-Ga2S3 transparent glasses. Raman spectroscopy reveals that RS-Ga2S3 glasses consist of the network of GeS4 tetrahedra due to the RS addition. The compositional dependence of molar volume indicates a plateau region at 65-70 mol% RS in SrS- and BaS-Ga2S3 glasses. The morphology of sulfur complex anions in RS-Ga2S3 glass melts is discussed using the sulfur-to-gallium ratio as a variable parameter. The combined results suggest that well-developed glass networks are formed near 66.7 mol% RS (S/Ga = 2.5) in the SrS- and BaS-Ga2S3 systems.

DOI： 10.2109/jcersj.111.308

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The solubility of Dy3+ ions in binary Ge-S glasses is studied. A mixture of Dy2S3, Ge and S raw materials in a silica ampoule was sealed under vacuum with 1-2 × 104 Pa, melted at 1000°C for 20 h with a slow rotation rate of &lt
1 rpm and then quenched to room temperature to form a glass. The solubility is evaluated by naked eye, optical microscopy and absorption measurements in glass samples. A linear relation between absorption coefficient and Dy2S3 concentration is obtained for the 6H15/2→6H9/12, 6F11/2 transition in the dissolved glasses. The dissolved concentration of Dy2S3 increases with decreasing S concentration in the Ge-excess compositions under 66.7 mol% S. A solubility model is proposed based on GeS2-like clusters existing in Ge-S glass melts. The dissolved concentration of Dy2S3 is at least 4 mass% (∼4 × 1026 Dy/m3) at 60-62 mol% S (38-40 mol% Ge). This relatively-high solubility is related to the existence of Ge2+ modifier ions as discussed in our previous study.

DOI： 10.2109/jcersj.111.168

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：FREUND PUBLISHING HOUSE LTD  

This article reviews the phase diagrams contributing to the understanding of compound formations, phase transformations, phase separation and microstructural development in advanced ceramic systems. Phase equilibrium relations in the Al2O3-AlN and AIN-B2O3 systems are presented for the fabrication of translucent aluminum oxynitride spinel ceramics and in-situ hexagonal boron nitride composites. In oxide systems, especially in glass-forming systems, crystallized phases vary with not only composition and temperature but also time of heat-treatment. Considering this aspect, time-temperature-transformation (TTT) diagrams in the solidification processes of cordierite, high-T-c superconducting oxide and fluorphlogopite melts and the phase transformations of ammonium aluminum carbonate hydroxide to alpha-alumina are introduced and specific phase transformations in these systems are also discussed. The effect of treatment atmosphere on microstructure in phase transformations is described in the surface-treatment of AlN ceramics and the sintering of transparent silica glass.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Materials Science Japan  

Six different types if ZrO2/Ni composite materials were fabricated by means of the slip casting method to study the effects of composition and dispersiveness on their deformation and fracture properties. The result of three-point bend testing indicated that the composition has significant influence on the bend strength and absorbed fracture energy with sufficient dispersiveness, whereas there was little effect on these properties with insufficient dispersiveness. The result of mode I fracture testing also exhibited that the critical mode I energy release rate, GIc, depended upon the composition, and the sufficient dispersiveness resulted in better GIc than the insufficient dispersiveness. The microstructures and fracture behaviors of the composites were examined using a laser microscope, an optical microscope with an image analysis technique and a scanning electron microscope (SEM). The result of the image analysis showed that the compositions of the sintered materials were different from those of the compacts. The SEM observation also exhibited that in the materials with insufficient dispersiveness, cracks tended to propagate along the interfaces of Ni aggregations, resulting in the degradation of the fracture properties.

DOI： 10.2472/jsms.51.489

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence (XRF) and Raman spectroscopies have been used to characterize the structure of Ge-S binary glasses in the compositional range 57-90 at.% S, together with evaluating the valences of Ge and S. XPS reveals that Ge4+ and Ge2+ states are formed and especially, Ge2+ exists in the range 57-62 at.% S. The roles of Ge4+- and Ge2+-relating species in glass structure are discussed. The combined results of XRF and Raman spectroscopies suggest that S-S bonds are present in all the S-rich glasses of &gt; 67 at.% S, short S chains are formed up to 76.5 at.% S and then S-8 rings are formed at the S-richer side. The compositional dependence of the molar volume calculated from the measured densities of glasses is qualitatively related to the structural units of the Ge-S glasses. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(01)00820-1

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Authorship：Corresponding author   Language：English   Publisher：ELSEVIER SCIENCE BV  

Thermal properties of gallium-lanthanum sulphide and oxysulphide glasses relevant to fiber applications are evaluated. Time-temperature-transformation diagrams of gallium-lanthanum sulphide and oxysulphide glasses are presented based on the results of X-ray diffraction analysis and microstructural observations. Thermal stability of these glasses for fiber drawing is discussed along with the viscosity data of supercooled liquid samples. Favourable fabrication conditions for gallium-lanthanum sulphide glass fibers are proposed to minimize microcrystal formation during heating. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(99)00540-2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Silica glass samples prepared by a sol-gel process, the mixture of silica sol for gelation and colloidal silica particles, have been thermally poled in vacuum by continuous high voltage (8-12 kV) at elevated temperature (280 degrees C). High second-order nonlinearities (&gt;1 pm/V), located under the anodic surface, have been measured and the values are higher than those obtained in fused silica glass, poled under the same conditions. A model for thermal poling is suggested which explains the experimental results in sol-gel silica and the difference between thermal poling of sol-gel and fused silica. The granular structure and the boundaries of sol-gel silica seem to play a major role in establishing the electrical properties of the depletion layer during and after poling. (C) 1999 American Institute of Physics. [S0003-6951(99)02418-3].

DOI： 10.1063/1.123903

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Refractive indexes were measured for Ga2S3-La2S3 and Ga2S3-La2O3 samples in the range of 0.48-1.71 nm using the minimum deviation method. Data are analyzed by the Wemple equation, which is based on the single-oscillator model. These samples have relatively large average bandgaps, E0, and electronic oscillator strengths, Ed, in comparison with other chalcogenide glasses. Possible origins of these features are discussed. © 1998 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(98)00737-6

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Language：Japanese   Publisher：The Mining and Materials Processing Institute of Japan  

The preparation process of Ge-Ga-S glasses is studied and its glass-forming region is presented. The effects of Ga and S contents on properties：glass transition temperature, density, and refractive index are investigated. The S content dependence of glass transition temperature and refractive index are divided into three regions relating to three bond types：1)the cation excess region with the contribution of Ge-Ge bonds, 2)an anion excess region with the dominant contributions of GeS2 tetrahedra connected by the S-S bonds, and 3)the other anion excess region with the contributions of S-S bonds and S8 rings. The solubilities of rare earth ion, Nd3+ in Ge-Ga-S, Ge-In-S and Ge-Sb-S glass systems are discussed using ionicity parameter, which based on the electronegativity between cation and sulfide anion.

DOI： 10.2473/shigentosozai.114.581

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Point defects were found in as-quenched GeO2, 65CaO . 35Al(2)O(3), and 65SrO . 35Ga(2)O(3) glasses on the basis of electron paramagnetic resonance (EPR) measurements. These defects were identified as Ge E' centers in GeO2 glass and O-2(-), O-3(-) and M-OHC (oxygen hole center) (where M = Al, Ga) in 65CaO . 35Al(2)O(3) and 65SrO.35Ga(2)O(3) glasses. The formation of Ge E' centers in as-quenched GeO2 glass was due to the thermodynamic stability of GeO at the melting temperature. The latter oxygen-excess defects are supposed to be formed by excess oxygen ions derived from the modifiers in the aluminate and gallate glasses during the formation of these glasses. To investigate some of the properties of the oxygen-excess defects in the calcium aluminate and strontium gallate glasses, chromium ions were doped in these glasses as a probe and the relationship between the valency state of the chromium ion and the defects was determined. We conclude that the peroxy bonding (-O-O-) oxidizes the Cr3+ species to Cr4+. Similar defects have been identified in host compounds that are used for Cr4+ tunable lasers, These results reveal that the point defects are necessary to stabilize the Cr4+ ions in glasses and crystals.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

Upconversion fluorescences of the green S-4(3/2) --&gt; I-4(15/2) and red F-4(9/2) --&gt; I-4(15/2) transitions of the Er3+ ion are studied for Yb3+ - and Er3+-codoped sodium germanate, potassium tantalum gallate, and barium tellurite glasses by InGaAs laser-diode pumping. The phonon energies of the host glasses are determined by infrared-reflection measurements. Compositional effects on the Jud-Ofelt parameters for the Er3+ ion, the spontaneous emission probability (SPE) of the F-2(5/2) --&gt; F-2(7/2) transition for the Yb3+ ion, and the phonon energy of the glass network are discussed in terms of glass structure. The factors that affect the upconversion fluorescence intensities of the Er3+ ion are discussed, using the phonon energy of the host glass and the SPE for the Yb3+ ion in the germanate, gallate, and tellurite glasses.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人日本セラミックス協会  

Phase transformations during the isothermal heat treatments of alkaline-earth aluminosilicate glasses with compositions of RO・Al_2O_3・2SiO_2(R=Mg, Ca, Sr, Ba)were studied based on the time-temperature-transformation(TTT)diagram. The crystallization conditions of metastable and stable phases such as cordierite(MgO・Al_2O_3・2.5SiO_2), anorthite(CaO・Al_2O_3・2SiO_2)and celsian(SrO・Al_2O_3・2SiO_2, BaO・Al_2O_3・2SiO_2), are determined. The onset time of crystallization is related to the viscosity of supercooled liquid measured in the previous works. The transformation processes of metastable-to-stable phases are discussed in terms of anion structure and cation radius.

DOI： 10.2109/jcersj.105.1109

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Green compacts of high-purity silica powders with different particle sizes were formed by slip casting method and pressureless-sintered. Conditions to fabricate transparent silica glasses are presented using diagrams described by sintering-temperature and -time. The variation of linear shrinkage with time reveals that the sintering mechanism at its early stage follows the viscous flow of silica glass particles. The effect of firing schedule on residual OH concentration was studied for transparent sintered silica glasses. A green compact prepared by silica powders with a mean particle size of 1.6 μm was fired at 1573 K for 3h for dehydration and heated up to 1873 K for densification; this typical fabrication condition results in a transparent sintered silica glass with&lt;1 ppm OH concentration.

DOI： 10.2109/jcersj.105.171

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Absorption spectra of Cr ions in multi-component oxide glasses melted in Ar were measured. The integrated extinction coefficient is used as a parameter to analyze the redox reaction of Cr3+ and Cr6+ in glass samples, The relative content of Cr6+ increased and that of Cr3+ decreased with increasing basicity in silicate and berate glasses; this result is consistent with previous studies. On the contrary, only Cr3+ ions exist in phosphate glasses. Cr4+ ions were found only in aluminate, gallate and alumino-silicate glasses with modifier contents greater than or equal to 60 mol%. The relationship between point defects and Cr4+ formation is examined on the basis of electron spin resonance measurements. We concluded that the superoxide ion radical (O-2(-)) and the peroxy bonding (-O-O-) oxidize Cr3+ to Cr4+ in aluminate, gallate, and alumino-silicate glasses, (C) 1997 Elsevier Science B.V.

DOI： 10.1016/S0022-3093(97)00264-0

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Absorption and fluorescence spectra of Nd3+ were measured in potassium tantalum gallate, lead bismuth gallate (PBG), fluorozirconate (ZBLAN), and Ge-Ga-S glasses. A Judd-Ofelt analysis was performed to determine the spontaneous emission probability and stimulated emission cross section of the 4F3/2 → 4I11/2 transition of Nd3+. Raman spectra were studied to clarify the maximum phonon energies of the glasses. The fluorescence of the 1G4 → 3H5 transition of Pr3+ in a dehydrated PBG glass was observed for the first time to our knowledge. The PBG glass has a higher quantum efficiency than that of ZBLAN glass based on the Judd-Ofelt analysis. © 1997 Optical Society of America.

DOI： 10.1364/AO.36.005839

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

Recent developments in the application of poled optical fibers to second harmonic generation and electrooptic Light modulation are reviewed.

DOI： 10.1109/50.618381

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

Absorption and fluorescence spectra of Nd3+ were measured in potassium tantalum gallate, lead bismuth gallate (PEG), fluorozirconate (ZBLAN), and Ge-Ga-S glasses. A Judd-Ofelt analysis was performed to determine the spontaneous emission probability and stimulated emission cross section of the F-4(3/2) --&gt; I-4(11/2) transition of Nd3+. Raman spectra were studied to clarify the maximum phonon energies of the glasses. The fluorescence of the (1)G(4) --&gt; H-3(5) transition of Pr3+ in a dehydrated PEG glass was observed for the first time to our knowledge. The PEG glass has a higher quantum efficiency than that of ZBLAN glass based on the Judd-Ofelt analysis. (C) 1997 Optical Society of America.

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The preparation and purification of Ge-Ga-S glasses were studied. A purified glass doped with 1000 ppm Pr3+ exhibits a quantum efficiency of 50% in the (1)G(4)--&gt;H-3(5) transition at 1.3 mu m based on fluorescence lifetime measurement and Judd-Ofelt analysis. The effects of Ga and S contents on glass transition and crystallization temperatures, density, refractive index and spontaneous emission probabilities from the F-4(3/2) level of Nd3+ were examined. Compositional dependences of properties are discussed in terms of bond types.

DOI： 10.1016/S0022-3093(96)00655-2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

Interaction between 96% alumina and three binary glasses used as frits in thick-film technology is studied, A possible interfacial reaction mechanism where a melt glass penetrates into the alumina through the grain boundaries dissolving SiO2, one of the grain boundary components, is suggested, The formulation expressing the glass penetration rate into the alumina based on Poiseuille's law, assuming the driving force for the glass penetration is the capillary force, is consistent with the experimental growth rate of the reaction layer in the alumina, The formulation also clearly explains the relationship of the degree of glass penetration to the viscosity and the surface tension of the melt glass, The extraordinary difference in K, designated as the coefficient of penetration, between the calculated result and the experimental result suggests that the process of dissolving SiO2 into a melt glass at the alumina grain boundaries retards the glass penetration.

DOI： 10.1111/j.1151-2916.1997.tb03020.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Refractive index dispersion curves in the wavelength region of 0.40 to 5.03 mu m are presented for multi-component oxide glass systems: berate, silicate, aluminate, germanate, tellurite, antimonate and heavy metal gallate. The material dispersion was determined using the refractive index data. Reflection spectra in the ultraviolet and infrared regions were measured to investigate the effects of electronic transitions and lattice vibrations on the material dispersion. Thallium tellurite, thallium antimonate and lead gallate glasses exhibit zero material dispersion wavelengths (ZMDWs) over 2.3 mu m. The factors affecting the ZMDW an discussed.

DOI： 10.1016/S0022-3093(96)00609-6

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Language：Japanese   Publisher：公益社団法人日本セラミックス協会  

Green compacts of high-purity silica powders with different particle sizes were formed by slip casting method and pressureless-sintered. Conditions to fabricate transparent silica glasses are presented using diagrams described by sintering-temperature and -time. The variation of linear shrinkage with time reveals that the sintering mechanism at its early stage follows the viscous flow of silica glass particles. The effect of firing schedule on residual OH concentration was studied for transparent sintered silica glasses. A green compact prepared by silica powders with a mean particle size of 1.6 μm was fired at 1573 K for 3h for dehydration and heated up to 1873 K for densification; this typical fabrication condition results in a transparent sintered silica glass with &lt;1 ppm OH concentration.

DOI： 10.2109/jcersj.105.171

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Second harmonic generation in gallium-lanthanum-sulphide (Ga:La:S) and germanium sulphide + Ga:La:S glasses is investigated. It is shown that microcrystals of Ga:La:S and alpha phase of gallium-sulphide (alpha-Ga2S3), whose presence in the glass matrix is revealed by energy dispersive spectroscopy and x-ray diffraction analysis, are responsible for the frequency doubling process. (C) 1997 American Institute of Physics.

DOI： 10.1063/1.118345

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To prepare α-cordierite glass ceramics, we demonstrate two types of phase diagrams of a composition 2MgO·2Al2O3·5SiO2 with time courses. One is the continuous-cooling-transforrnation (CCT) diagram; the other is the temperature-time-transformation (TTT) diagram. At - 1273 K, n-cordierite is crystallized as the primary phase and then it transforms to a-cordierite with a lath-like martensite transformation. The volume expansion derived from this transformation results in a lot of cracks in crystallized glasses. Since the addition of MgF2 for the substitution of MgO (ca. 5%) suppresses the u-to a-cordierite transformation but promotes the direct crystallization of α-cordierite from glass, we can prepare α-cordierite glass ceramics without cracks. In this paper, we point out the needs and usefulness of CCT and TTT diagrams for glass ceramics processing. © VCH Verlagsgesellschaft mbH, 1996.

DOI： 10.1002/bbpc.19961000911

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

The Judd-Ofelt parameters, spontaneous emission probabilities from the 4F3/2 level, quantum efficiency, and stimulated emission cross section of the 4F3/2→4I11/2 transition for Nd3+ are studied for potassium tantalum and lead bismuth gallate glasses. The results reveal that the tantalum gallate glasses have high Ω2 values being comparable to that of Ge-Ga-S glass. The lead bismuth gallate glasses have high stimulated emission cross sections over 4 pm2 because of their high refractive indexes. The variations of the JO parameters with composition are discussed in terms of glass structure.

DOI： 10.2109/jcersj.104.243

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OPTICAL SOC AMER  

A systematic study of the effects of poling time and applied voltage on second-harmonic (SH) generation in thermally poled silica glass reveals that the SH signal is proportional to the square of the applied voltage and that the speed of the poling process increases with the applied voltage. Prior treatment of the samples is found to affect the poling process, and the optimum poling conditions are observed to depend on the poling atmosphere. The mechanism of thermal poling is discussed in the light of these new results. (C) 1996 Optical Society of America

DOI： 10.1364/OL.21.000468

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

The integrated absorption cross section, the spontaneous emission probability, and the stimulated emission cross section of Yb3+ were determined in silicate, phosphate, borate, germanate, aluminate, gallate, and ZBLAN host glasses, The compositional dependence of the stimulated emission cross section of the F-2(5/2) --&gt; F-2(7/2) transition is determined mainly by the integrated absorption cross section in the glasses. A peak stimulated emission cross section above 1 pm(2), which is the highest value in glasses, was obtained in a gallate glass with a composition of 40K(2)O . 20Ta(2)O(5) . 40Ga(2)O(3). The factors affecting the integrated absorption cross section are discussed using the Judd-Ofelt parameters of Er3+ calculated in previous studies.

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Language：Japanese   Publisher：公益社団法人日本セラミックス協会  

The Judd-Ofelt parameters, spontaneous emission probabilities from the ^4F_&lt;3/2&gt; level, quantum efficiency, and stimulated emission cross section of the ^4F_&lt;3/2&gt;→^4I&lt;11/2&gt; transition for Nd^&lt;3+&gt; are studied for potassium tantalum and lead bismuth gallate glasses. The results reveal that the tantalum gallate glasses have high Ω_2 values being comparable to that of Ge-Ga-S glass. The lead bismuth gallate glasses have high stimulated emission cross sections over 4 pm^2 because of their high refractive indexes. The variations of the JO parameters with composition are discussed in terms of glass structure.

DOI： 10.2109/jcersj.104.243

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Accurate refractive indexes of Na2O-GeO2 glasses containing 5-30 mol% Na2O were measured in the wavelength range of 0.334 to 1.710 mu m using the minimum deviation method. The influence of glass structure on the refractive index and its dispersion has been discussed in terms of the number of the oxygen ion in a unit volume and the apparent refractivity of the oxygen ion. With the addition of Na2O, the refractive index n(d) increased at 5&lt;Na2O&lt;15 mol%, showed a maximum around 15 mol% Na2O, and decreased with further addition. The Abbe number nu(d) decreased monotonically. The variations of n(d) and nu(d) with Na2O content were related to the oxygen coordination number of Ge ions.

DOI： 10.2109/jcersj.103.886

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Language：Japanese   Publisher：公益社団法人日本セラミックス協会  

Accurate refractive indexes of Na_2O-GeO_2 glasses containing 5-30 mol% Na_2O were measured in the wavelength range of 0.334 to 1.710 μm using the minimum deviation method. The influence of glass structure on the refractive index and its dispersion has been discussed in terms of the number of the oxygen ion in a unit volume and the apparent refractivity of the oxygen ion. With the addition of Na_2O, the refractive index n_d increased at 5&lt;Na_2O&lt;15 mol%, showed a maximum around 15 mol% Na_2O, and decreased with further addition. The Abbe number ν_d decreased monotonically. The variations of n_d and ν_d with Na_2O content were related to the oxygen coordination number of Ge ions.

DOI： 10.2109/jcersj.103.886

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC 735 CERAMIC PLACE  

Judd-Ofelt parameters Omega(t) with t = 2, 4, 6 for the rare-earth ions pr(3+), Nd3+, Sm3+, Tb3+, Dy3+, Ho3+, Er3+, and Tm3+ in alkali and/or alkaline earth silicate, borate, and phosphate glasses have been determined. The variations of Omega(t) with the number of 4f electrons of the rare-earth ions are demonstrated, and factors affecting the Judd-Ofelt parameter Omega(6) are discussed. The intensity parameter Omega(6) depends on the ionic packing ratio of the glass host by changing modifier type in silicate and borate glasses, and it is independent of that in a series of borate glasses as a function of modifier content and phosphate glasses. The peak wavenumbers of the transitions whose intensities are determined mainly by the Omega(6)[\\U-(6)\\](2) term-where [\\U-(6)\\] is one of the reduced matrix elements-shift systematically with the values of Omega(6) for all the rare-earth ions.

DOI： 10.1111/j.1151-2916.1995.tb08463.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC 735 CERAMIC PLACE  

Accurate refractive indexes of oxide glasses--silica, silicate, berate, aluminate, tellurite, antimonate, and heavy metal gallate glasses-are presented in the wavelength range 0.265 to 1.710 mu m. Factors affecting the refractive index dispersion are discussed by using the single-oscillator Drude-Voigt equation. The values of n(d) at 0.5876 mu m are affected mainly by the average resonance wavelength at the ultraviolet region through all of the glass systems, The distinguishing features of berate glasses-relatively high refractive index and low dispersion-are related to the large number of molecules, N, in a unit volume, compared with those of the other glasses, The number N determined by density measurements is related to the fraction of the four-coordinated borons estimated by Greenblatt and Bray.

DOI： 10.1111/j.1151-2916.1995.tb08466.x

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人日本セラミックス協会  

The effects of composition on refractive index, density, glass transition temperature, and ultaviolet-visible and infrared transmissions were studied for gallate glasses containing a large amount (80 mol%) of PbO, Bi_2O_3 and Tl_2O. The resonance wavelengths of Pb^&lt;2+&gt;Bi^&lt;3+&gt; and Tl^+ were determined from the reflection spectra of gallate glasses. The refractive indexes of gallate glasses were measured down to the fourth decimal in the wavelength range of 480 nm to 1710 nm using the minimum deviation method. Refractive index in the system Bi_2O_3-PbO-Ga_2O_3 increases as PbO is substituted for Bi_2O_3. Refractive index in the systems Tl_2O-PbO-Ga_2O_3 and Tl_2O-Bi_2O_3-Ga_2O_3 increases as Tl_2O content increases. Factors affecting the refractive index of heavy metal gallate glasses are discussed by using the single-oscillator Drude-Voigt equation.

DOI： 10.2109/jcersj.103.340

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ceramic Soc of Japan  

Accurate refractive indexes of Na2O-GeO2 glasses containing 5-30 mol% Na2O were measured in the wavelength range of 0.334 to 1.710 μm using the minimum deviation method. The influence of glass structure on the refractive index and its dispersion has been discussed in terms of the number of the oxygen ion in a unit volume and the apparent refractivity of the oxygen ion. With the addition of Na2O, the refractive index nd increased at 5&lt
Na2O&lt
15 mol%, showed a maximum around 15 mol% Na2O, and decreased with further addition. The Abbe number vd decreased monotonically. The variations of nd and vd with Na2O content were related to the oxygen coordination number of Ge ions.

DOI： 10.2109/jcersj.103.886

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

Refractive indexes of barium borate-based glasses were measured in the wavelength range from 0.265 to 1.710 mu m by using the minimum deviation method. Factors affecting the refractive index dispersion are discussed by using the single-oscillator Drude-Voigt equation. Borate glasses are characterized by the larger number N of molecules in a unit volume than that for silicate glasses, The feature of borate glasses, that is, relative high refractive index and low dispersion, is dominated by the number N which is related to the fraction of four-coordinated borons estimated by Greenblatt and Bray, Borate glasses containing high valency cations, e.g., Y3+, La3+, Ti4+, Nb5+, Ta5+, posess higher refractive indexes and higher dispersion than barium borate binary glasses.

DOI： 10.2109/jcersj.102.1163

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC 735 CERAMIC PLACE  

Absorption spectra of Ti3+ were measured for silicate, borate, and phosphate glasses doped with 0.5 mol% Ti2O3. The absorption coefficient at the peak wavelength of the T-2(2) --&gt; (2)E transition of Ti3+ is used as a parameter showing the relative content of Ti3+ ions in glass samples. The effect of glass composition on Ti3+/Ti4+ redox was studied. For multicomponent glasses, a basicity parameter calculated from glass composition is proposed in terms of coulomb force between the cation and the oxygen ion. The value of the absorption coefficient depends on basicity in silicate and borate glasses; however, it is independent of composition in phosphate glasses.

DOI： 10.1111/j.1151-2916.1994.tb04557.x

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The compositional dependences of spontaneous emission probabilities of rare-earth ions such as Nd3+ and Er3+ were studied for silicate, phosphate and berate glasses using the Judd-Ofelt theory. The effect of the covalency of the rare-earth ion sites on the emission probabilities was estimated from the variations of the profiles of the absorption spectra in terms of the nephelauxetic effect. The spontaneous emission probabilities which depended on the intensity parameters, Omega(4) and Omega(6), were strongly affected by the ionic packing ratio of the glass host.

DOI： 10.1016/0022-3093(94)90265-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN INST METALS  

For X-ray amorphous Pd82Si18 and Fe80B20 alloys prepared by a melt-spinning method with various wheel velocities, the relationship between the heat of crystallization and microstructure was studied using differential scanning calorimetry and optical and transmission electron microscopy. The result of TEM shows that the X-ray amorphous Pd82Si18 alloy has a uniform microstructure without crystals and the X-ray amorphous Fe80B20 alloy contains uniformly-dispersed alpha-Fe particles with nanometer sizes which are undetectable by the ordinary X-ray diffraction analysis. The Avrami exponent n for the crystallization of the X-ray amorphous alloys supports the microstructural features. The variations in the heat of crystallization with the cooling rate estimated from the ribbon thickness correspond to the volume fraction of crystalline phases for Pd82Si18 alloys and the particle size of alpha-Fe for Fe80B20 alloys. The heat of crystallization is proposed as a parameter expressing the degree of non-crystallinity for the alloys. The critical cooling rates for the formation of X-ray amorphous phases mean the minimum cooling rate to avoid the formation of crystals with a detectable ''volume fraction'' for Pd82Si18 alloys and that with a detectable ''size'' for Fe80B20 alloys.

DOI： 10.2320/matertrans1989.35.708

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Authorship：Lead author   Language：English   Publisher：AMER CERAMIC SOC  

The refractive index of binary tellurite glasses with various modifiers was measured down to the fifth decimal place in the wavelength range of 0.40-1.71 mu m using the minimum-deviation method. An empirical equation based on the single-oscillator Drude-Voigt dispersion equation, n(d)(2) = A.Nf lambda(0)(2) + B, is obtained, where n(d) is the refractive index at 0.5876 mu m, N is the number of molecules in a unit volume, f is the average oscillator strength, lambda(0) is the average resonance wavelength, and A and B are constants. The refractive index n(d) of tellurite glasses is substantially determined by the resonance wavelength at the ultraviolet region, which is affected by the main constituent, TeO2.

DOI： 10.1111/j.1151-2916.1994.tb04621.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

Compositional dependence of spontaneous emission probabilities of Er3+ was studied for silicate, borate, and phosphate glasses using the Judd-Ofelt theory. Through all of the glass systems, spontaneous emission probabilities of the I-4(3/2) --&gt; I-4(15/2), I-4(9/2) --&gt; I-4(J), and S-4(3/2) --&gt; I-4(J) (J = 9/2, 11/2, 13/2, 15/2) transitions increased with increased ionic packing ratio of the glass host, which varied markedly with the type of network modifier. The effect of Er-O covalency on the transition probabilities was discussed from the spectral profile of the I-4(15/2) --&gt; S-4(3/2) transition in terms of nephelauxetic effect.

DOI： 10.1111/j.1151-2916.1994.tb07108.x

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DOI： 10.2473/shigentosozai.110.701

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A powder processing technique has been developed for the fabrication of tetragonal zirconia-nickel functionally gradient materials using slip casting and pressureless-sintering. Rheological behavior of slips was studied. Single-layer zirconia-nickel green compacts with various zirconia/nickel volume ratios were characterized by permeability and pore radius. A multilayer zirconia-nickel green compacts with a stepwise compositional gradient was formed and sintered in argon atmosphere. One of the keys to successful fabrication was to minimize differences in permeability and pore radius between neighbouring layers in a multilayer green compact to avoid fracture during drying in an ambient atmosphere. © 1994, Taylor &amp
Francis Group, LLC. All rights reserved.

DOI： 10.1080/10426919408934942

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JAPAN INST METALS  

Phase transformations of cordierite (2MgO . 2Al2O3 . 5SiO2) glasses have been studied by X-ray diffraction, differential thermal analysis (DTA), optical microscopy (OM), and transmission electron microscopy (TEM). Continuous-Heating-Transformation (CHT) diagram and Time-Temperature-Transformation (TTT) diagrams are proposed. Continuous heating of bulk and powder glasses at 0.005 approximately 0.33 K/s leads to the initial crystallization of mu-cordierite and subsequent mu--&gt;alpha transformation. There are two transformation processes in isothermal treatments of bulk glasses at 1123 approximately 1473 K: One is the transformation from mu-cordierite to alpha-cordierite and the other is the direct crystallization from glass to alpha-cordierite. The microstructures of alpha-cordierite are affected by the transformation processes. The alpha-cordierite crystals transformed from mu-cordierite crystals contain microcracks, dislocations, and planar faults. The alpha-cordierite crystals formed directly from the glass show needle-like segments extending three dimensionally from the center. For powder glasses, isothermal treatments at 1123 approximately 1473 K lead only to the mu--&gt;alpha transformation. This is due to the predominant nucleation of mu-cordierite on the surface of the glasses.

DOI： 10.2320/jinstmet1952.58.7_720

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The reaction and phase changes of the AlN-B2O3 Mixtures with 5-33.3 mol% B2O3 was studied at high temperatures up to 1800-degrees-C. Boron nitride (BN), Al2O3, 2Al2O3 . B2O3, 9Al2O3.2B2O3, and aluminum oxynitride spinel (AlON) are formed during the reactions. Phases of product formed at 1800-degrees-C are BN, AlON, Al2O3, and AlN. The effect of the formation mechanism of AlON on the growth of BN grains is discussed. The phase relation diagram is proposed based on the reaction results.

DOI： 10.2320/matertrans1989.35.258

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Fluorescence and absorption spectra of Eu3+ in silicate glasses have been measured. The fluorescence intensity ratio of 5D0 → 7F2 to 5D0 → 7F1 transitions of Eu3+ increases with increasing ionic radius in the order of Li &lt
Na &lt
K for binary alkali silicate glasses and with decreasing ionic radius in the order of Ba &lt
Sr &lt
Ca for binary alkaline earth silicate glasses. It was found for the first time that the intensity ratio exhibited a maximum with the addition of alkaline earth oxides in alkali alkaline earth silicate glasses. The variation of intensity ratio and the Judd-Ofelt parameter, Ω2, with composition depended on the structural change in the vicinity of Eu3+ ions and EuO covalency. © 1994.

DOI： 10.1016/0022-3093(94)90324-7

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CERAMIC SOC  

Compositional dependence of spontaneous emission probabilities between initial F-4(3/2) and terminal I-4(J) (J = 9/2, 11/2, 13/2, 15/2) levels of Nd'' were studied for about 90 samples of silicate, borate, and phosphate glasses using the Judd-Ofelt theory. The effect of the covalency of the Nd-O bond on the magnitude of intensity parameters was estimated from the variation of spectral profiles of the I-4(9.2) --&gt; G-4(5/2), 2G7/2 and F-4(7/2), S-4(3/2) transitions. Intensity parameters OMEGA4 and OEMGA6 and the spontaneous emission probabilities were strongly affected by the ionic packing ratio of the glass host. The results were discussed in terms of the site selectivity of Nd3+ ions in glasses.

DOI： 10.1111/j.1151-2916.1993.tb06612.x

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The basic principle behind this study is the utilization of the density difference among the species used and the size difference among the particles within the powders used to influence the sedimentation velocity of particles in a slip. A continuous functionally gradient material was fabricated using the slip casting method. This material is different from conventional functionally gradient materials prepared by other methods in that the composition of this material varies continuously rather than in a layer-by-layer fashion. In a continuous functionally gradient material, problems associated with interfaces between layers or films of different compositions, which are shared among almost all conventional functionally gradient materials, are eliminated. An Al2O3-W-Ni-Cr system was used in this study. Processing conditions were reported. Compositional gradients within this type of samples were examined. Thermal expansion, fracture toughness, hardness, and electrical resistance were evaluated.

DOI： 10.2109/jcersj.101.841

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：MINERALS, METALS & MATERIALS SOC  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

The critical cooling rate required for the formation of glass is one of the important characteristics for silicate slag. The critical cooling rates have been measured for R2O(R=Li, Na and K)-SiO2 and R'O(R'=Ca, Sr and Ba)-SiO2 systems by the combined use of the hot-thermocouple method and an ordinary melt-quenching method. In all systems, the minima in critical cooling rate corresponded with the com-position range of low liquidus temperatures near the eutectics; the critical cooling rates decreased with increasing viscosities at the liquidus temperatures. The measured critical cooling rates were similar to those predicted by the Uhlmann equation and Ota equation. Some factors affecting the critical cooling rate were discussed.

DOI： 10.2355/isijinternational.33.233

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Alumina suspensions for extrusion were prepared by adding metylcellulose and glycerol to a system of water, ammonium polyacrylic acid, and alumina powder. The effect of the additives on the rheology of mixtures was evaluated. The mixtures which could be formed into a sheet of less than 100 μm in thickness showed Bingham flow characteristics. As the flow characteristics of the mixture, an empirical equation, P/k=A+B ln R, was obtained, where P is the extrusion pressure for forming alumina sheets, k is the apparent yield stress of the mixture, A and B are constants, and R is the extrusion ratio. The effect of methylcellulose and glycerol on the particle packing and the flexibility of alumina green sheets was discussed. A dense, translucent, alumina sheet of 80μm thick was obtained after firing at 1400℃ for 4 h.

DOI： 10.2109/jcersj.100.750

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A powder processing technique is developed for the fabrication of tetragonal zirconia-nickel functionally gradient materials. The powder volume fraction, the linear shrinkage during drying, and the pore radius of monolithic zirconia-nickel green compacts with various zirconia/nickel volume ratios were measured. A multilayer zirconia-nickel green compact with a stepwise compositional gradient was formed by slip casting and then pressureless-sintered. The key to successful fabrication is to avoid the fracture of green compact during drying process in an ambient atmosphere. In conclusion, it is desirable to minimize differences in permeability and pore radius between neighboring layers in a multilayer green compact.

DOI： 10.2109/jcersj.100.387

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Language：Japanese   Publisher：公益社団法人日本セラミックス協会  

Oxidation behavior of sintered AlN by oxygen and water vapor was studied at 1400°C for the purpose of surface treatment. The partial pressure of oxygen, &lt;i&gt;P&lt;/i&gt;&lt;sub&gt;o&lt;sub&gt;2&lt;/sub&gt;&lt;/sub&gt; was controlled at 10&lt;sup&gt;-10&lt;/sup&gt; and 10kPa, and that of water vapor, &lt;i&gt;P&lt;/i&gt;&lt;sub&gt;H&lt;sub&gt;2&lt;/sub&gt;O&lt;/sub&gt; was changed at 5.0×10&lt;sup&gt;-2&lt;/sup&gt; to 8.5kPa. The oxidation product detected by XRD was α-Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;. Oxidation rate was increased with increasing &lt;i&gt;P&lt;/i&gt;&lt;sub&gt;H&lt;sub&gt;2&lt;/sub&gt;O&lt;/sub&gt;. The weight gain with time by oxygen was parabolic, and that by water vapor was linear. The Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; layer formed by the oxidation of sintered AlN with oxygen was relatively dense, and coherent. The oxidation kinetics were discussed using the mixed-control rate equation on the basis of unreacted-core model.

DOI： 10.2109/jcersj.100.70

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The thermal decomposition and the phase transformations of ammonium aluminum carbonate hydroxide (AACH) to α-alumina have been studied. Amorphous-, γ- and θ-alumina were identified as intermediate products. A TTT diagram for the process of the thermal decomposition and the phase transformations was determined. Kinetic analysis of the θ- to α-aluminas transformation by the Avrarni-Erofeev equation showed that the transformation occurred by the nucleation and growth mechanism. Results of transmission electron Microscopy (TEM), however, suggested that the transformation occurred by the synchro-shear mechanism. The maximum particle size of θ-alumina and the minimum particle size of α-alumina were approximately 30 and 40 nm, respectively. A model of the transformation was presented from the viewpoint of crystallography.

DOI： 10.2109/jcersj.99.550

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JAPAN INST METALS  

The tetragonal to monoclinic transformation in Y-TZP specimens and mullite/Y-TZP composites containing 5 vol% mullite, which progresses from surface to interior by annealing at 373 K in boiling water, was investigated by scanning acoustic microscope (SAM). The Rayleigh wave velocity, V(R), which was measured on surfaces of the specimens, was lowered by the transformation. We obtained relationships between the transformation depth which was converted from the V(R) and annealing time. The depth after the annealing for 612.0 ks in the Y-TZP specimens was 7.2-mu-m, while in the mullite/Y-TZP composites it was less than 1.0-mu-m. Apparently the relationships suggested that a nucleation-growth stage existed in the process of the transformation. The transformation mechanism was discussed from changes of the transformation depth and SAM image contrast with the annealing time.

DOI： 10.2320/jinstmet1952.54.12_1358

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A fabrication process of multilayer thick film was discussed. The film, consists of three-layered structure, was stacked with protective layers of Al_2O_3 against vapor attack on both sides of Y-TZP layer. Slip casting method was used to form a multilayer green body. The thickness of each layer in the green body was controlled on the basis of casting data which was calculated for Al_2O_3 and Y-TZP slips. To avoid fracture during in an ambient atmosphere, it was important to minimize differences in permeability and pore size between Al_2O_3 and Y-TZP layers. No cracking was observed in a multilayer-sintered body, when a densification rate of each layer in the early stage of sintering was equal. The dense multilayer thick film was obtained by firing at 1600℃ for 2 h.

DOI： 10.2109/jcersj.98.1250

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The process of fabricating yttria-stabilized zirconia (YSZ) tubes consisted of dense and porous layers for solid oxide fuel cell by the slip casting has been discussed. Two types of YSZ powders having different agglomerate particle sizes were used. The size of dispersed YSZ particles was controlled by changing the milling time of YSZ slips. YSZ green bodies consisted of two layers were formed by the slip casting. During the drying process in an ambient atmosphere, no delamination of layers developed for similar permeabilites of dense and porous layers. The sintered YSZ material having dense and porous layers with ralative densities of 96 and 70%, respectively, was obtained by firing at 1300℃ for 100 min. Because of a similarity of the densification rates of each layer in the early stage of sintering, cracks or defects were not observed in the sintered body. A YSZ tube consisted of dense and porous layers for SOFC was fabricated. The dense layer of electrolyte was 50 μm.

DOI： 10.2109/jcersj.98.1088

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The condition to get a cordierite (2MgO·2Al2O3·5SiO2) ceramics by the solidification of the melt has been discussed. &#039;Low&#039;-cordierite and μ-cordierite were identified in the process of the isothermal transformation at 1623-1673 K and 1223-1253 K, respectively. The μ-cordierite was transformed to the α-cordierite with increasing holding time of sample at 1223-1253 K. TTT diagram in the solidification of cordierite melt was measured. From the result of TEM, planar faults and dislocations were observed so that the transformation of μ-cordierite to α-cordierite was similar to the isothermal martensite transformation that occurred in the carbon steel.

DOI： 10.2320/jinstmet1952.54.5_556

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To fabricate the yttria-stablized zirconia (YSZ) films for solid oxide fuel cell by the slip casting, viscosity of YSZ slips and sintering property of green bodies have been investigated. Chlorine in as-received YSZ powders was removed as Cl^-ion by repetitive laundering of admixing distilled water. The sintering property of as-received YSZ powders was superior to that of laundered ones, because YSZ particles were condensed in the laundering process. Both as-received and laundered YSZ particles were stabilized in the slip with a deflocculant containing NH_4^+ salt of polyacrylic acid as a major component. For some slips the square of thickness of casting layer, L^2, was proportional to the casting time, t. Casting rate constant, L^2/t , was increased with increasing concentration of YSZ powders in the slips. The thickness of casting layer for fabricating YSZ films could be controlled by the casting data of YSZ slips. The relative densities of sintered YSZ specimens were 92 and 96% at sintering temperatures of 1300℃ and 1500℃, respectively. Dense YSZ films were fabricated by slip cast, and sintered without pressure at 1 500℃. The I-V characteristics of the flat thick film type solid oxide fuel cell based on the YSZ electrolyte film of 140μm thick, La_&lt;0.6&gt;Sr_&lt;0.4&gt;MnO_3 cathode and NiO + YSZ anode was excellent, and the power of this cell was about 450 m W/cm^2.

DOI： 10.2109/jcersj.98.136

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DOI： 10.2473/shigentosozai.105.1067

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Pressureless sintered hexagonal boron nitride (h-BN) was fabricated using turbostratic BN and amorphous B as starting powders. Bulk density and bending strength of the sintered BN with additives were increased compared to using pure h-BN as a starting powder. In sintered BN with 5 wt%SiC, high bending strength of 9 kg/mm2 was obtained in the range room temperature to 1200°C. On the other hand, sintered BN with 30 wt%AlN had superior corrosion resistance. These materials are applicable for the protective tube in continuous temperature measurement of molten steel in the range 1500 to 1560°C.

DOI： 10.2473/shigentosozai.105.201

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

The single-phase region of AION, a spinel type solid solution in the system Al_2O_3-AlN, has been determined. AION was synthesized from solid phase reactions between Al_2O_3 and AIN powder in several reaction vessels. The reaction vessel of porous Al_2O_3 with AIN coating was suitable for obtaining pure AION. The single-phase region of AION was from 28 to 32 mol% AIN at 1700℃ and from 20 to 34 mol% AIN at 1800℃. The lattice parameters of AION increased from 7.926 to 7.946A^^゜ with increasing AIN content. Y_2O_3-powder was used as a sintering aid to obtain translucent AION from synthesized AION powder at low temperature. For 1 wt% Y_2O_3 addition, the translucent AION was obtained at 1800℃, and its relative density and flexural strength were 99% and 250 MPa, respectively.

DOI： 10.2109/jcersj.97.166

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Lamellar Al_2O_3 ceramics were fabricated by the slip casting method, using two types of Al_2O_3 powders having different particle sizes and densification behavior between each other. The lamellar ceramics have the structure of alternating dense and porous layers with respective thickness, λ_p and λ_p, ranging from 60 to 500 μm, and the volume fraction of the dense layers. V_D, from O to 100%. The lamellar structures were controlled by changing the casting time and using the centrifugal force for draining the Al_2O_3 slurries during green forming. Fracture strengths of the lamellar ceramics were measured by three-point bending. Some of the lamellar ceramics showed higher flexural strength than monolithic, dense Al_2O_3 (〜335 MPa) . The maximum strength, 〜400 MPa, was obtained for the lamellar ceramic with V_D=89±3%, λ_p=500 μm, λ_p= 60 μm. The high strength is discussed from the view point of the crack deflection in the porous layers,

DOI： 10.2109/jcersj.96.1149

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This article reviews the fabrication and properties of sulfide glasses and thin films consisting of non-toxic elements: alkaline-earth, rare-earth, germanium and gallium sulfides for optical applications. Refractive indexes, transmission and the fluorescence property of rare-earth ions in sulfide glasses are presented. Factors affecting rare-earth solubility in sulfide glasses are summarized. Thermally-stable BaS-Ga2S3-GeS2 glasses for optical fibers and Nd3+-doped transparent Ga-La-S-O glass-ceramics are described as new optical materials. Sm-doped SrS-Ga2S3 non-crystalline and nano-crystalline metallic SmS films were irradiated by focused femtosecond laser pulses and new photoinduced phenomena are introduced.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：応用物理学会分科会日本光学会  

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Ge-S binary glasses in the range 57 to 90 at%S at 0.5 to 3 at%S intervals were prepared by a conventional melting technique using fused quartz ampoules as melting containers. Impurities contaminated during preparation process are evaluated by IR spectroscopy. The causes of impurity contaminations are discussed. Density data in a systematic series of Ge-S glasses is demonstrated.

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A review of electro-optic and nonlinear optical devices based on poled glass will be presented, including recent developments and potential applications.

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Bi2Sr2Ca2Cu3Ox (2223) phase is not formed but Bi2Sr2Ca2Cu3Ox (2212) and Bi2Sr2CuOx (2201) phases are observed during continuous cooling processes with the rates of 0.001 - 10°C/s. The time-temperature-transformation (TTT) diagram in the solidification of the melt is proposed based on X-ray diffraction (XRD) analysis. The high-Tc superconductor phase 2223 is formed through isothermal treatments at 850°C for over 150 ks. The results of XRD and scanning electron micrograph with energy dispersive X-ray microanalysis for the isothermal treatment show that 2201 needles are crystallized at the interface between the (Ca, Sr)2CuO3 crystal and the retaining super cooled liquid, and then a part of the 2201 phases transforms to 2212 and 2223 phases by the diffusion of Ca, Sr, and Cu ions.

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Refractive indexes were measured for Ga2S3-La2S3 and Ga2S3-La2O3 samples in the range of 0.48-1.71 μm using the minimum deviation method. Data are analyzed by the Wemple equation, which is based on the single-oscillator model. These samples have relatively large average bandgaps, E0, and electronic oscillator strengths, Ed, in comparison with other chalcogenide glasses. Possible origins of these features are discussed. © 1998 Elsevier Science B.V. All rights reserved.

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Language：English   Publisher：AMER CERAMIC SOC 735 CERAMIC PLACE  

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Zirconia-nickel composite materials were fabricated by powder processing technique and pressureless sintering. A tensile testing machine with a scanning electron microscope was utilized to study the deformation and fracture behaviors of the materials. Tensile tests were performed on dumbbell type specimens in vacuum at temperatures up to 800°C. Stress-strain relationships were determined for the composites as functions of temperature and volume fraction of ZrO2. The result showed that both the tensile strength and elongation to fracture decreased as the test temperature increased. It was also found that the strength increased with increasing volume fraction of ZrO2 up to 50%. To understand such effects, the deformation and fracture behaviors were investigated from microscopic view points through in-situ observation of the specimen surface and the fracture surface examination. © 1994, The Society of Materials Science, Japan. All rights reserved.

DOI： 10.2472/jsms.43.1463

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Language：English   Publisher：The Society of Materials Science, Japan  

Zirconia-nickel composite materials were fabricated by powder processing technique and pressureless sintering. A tensile testing machine with a scanning electron microscope was utilized to study the deformation and fracture behaviors of the materials. Tensile tests were performed on dumbbell type specimens in vacuum at temperatures up to 800°C. Stress-strain relationships were determined for the composites as functions of temperature and volume fraction of ZrO2. The result showed that both the tensile strength and elongation to fracture decreased as the test temperature increased. It was also found that the strength increased with increasing volume fraction of ZrO2 up to 50%. To understand such effects, the deformation and fracture behaviors were investigated from microscopic view points through in-situ observation of the specimen surface and the fracture surface examination. © 1994, The Society of Materials Science, Japan. All rights reserved.

DOI： 10.2472/jsms.43.1463

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Language：Japanese   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

DOI： 10.15017/17304

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