研究者詳細 - 山田　明寛

論文 - 山田　明寛

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Deformability of Mg–aluminosilicate glass under high pressure and shear stress: dynamic coordination change of Al³⁺ 査読

Kosei Osada, Akihiro Yamada, Koji Ohara, Satoshi Yoshida, Jun Matsuoka

Physical Chemistry Chemical Physics 2026年3月

Structural Changes upon Ambient Temperature Densification in Calcium Aluminoborosilicate Glasses: Relation to Indentation Crack Resistance 査読

Yara Hellen Firmo Gomes, Gustavo A. Rosales-Sosa, Shingo Nakane, Yoshinari Kato, Hiroki Yamazaki, Akihiro Yamada, Hellmut Ecker

2025年10月

Synthesis and structure of anisotropic borosilicate glasses under differential stress at high pressure and temperature 査読

Shingo Taniguchi, Akihiro Yamada, Tomohiro Ohuchi, Koji Ohara, Daisuke Shibata, Mizuki Nishiwaki, Jun Matsuoka

2025年6月

Indentation stress fields in brittle materials: A micro-photoelastic investigation in silicate glasses 査読国際共著

Gustavo Alberto Rosales-Sosa, Etienne Barthel, Yoshinari Kato, Matthieu Bourguignon, Akihiro Yamada, Tomiki Inoue, Shingo Nakane, Hiroki Yamazaki

Acta Materialia 292 2025年4月

Densification of sodium and magnesium aluminosilicate glasses at ambient temperature: structural investigations by solid-state nuclear magnetic resonance and molecular dynamics simulations 査読国際共著

Millena Logrado, Yara Hellen Firmo Gomes, Tomiki Inoue, Shingo Nakane, Yoshinari Kato, Hiroki Yamazaki, Akihiro Yamada and Hellmut Eckert

Physical Chemistry Chemical Physics 26 27348 - 27362 2024年10月

Structural Aspects of Ambient-Temperature Densification of Highly Crack-Resistant Borosilicate and Aluminoborosilicate Glasses: Two Case Studies Examined by Solid-State NMR 査読国際共著

Yara Hellen Firmo Gomes, Millena Logrado, Tomiki Inoue, Shingo Nakane, Yoshinari Kato, Hiroki Yamazaki, Akihiro Yamada and Hellmut Eckert

The Journal of Physical Chemistry B 128 ( 14 ) 3508 - 3520 2024年4月

Effect of grain size on amorphization mechanism and kinetics of bridgmanite in shocked meteorites

2023年7月

Densification of Sodium Borosilicate Glasses at Ambient Temperature: Structural Investigations by Solid-State Nuclear Magnetic Resonance and Raman Scattering 査読国際共著国際誌

Millena Logrado, Tomiki Inoue, Shingo Nakane, Yoshinari Kato, Hiroki Yamazaki, Akihiro Yamada, Hellmut Eckert

The Journal of Physical Chemistry Letters 14 4471 - 4481 2023年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Publications 参加形態：共同（副担当）

Alkali-borosilicate glasses with composition (80-x)SiO2-xB2O3-20Na2O (10 ≤ x ≤ 30) were subjected to a 25 GPa compression and decompression at room temperature, resulting in density increases between 1.4% and 1.9%. The structural changes associated with this process have been investigated and compared with uncompressed glasses having the same thermal history. Systematic trends are identified, using Raman scattering and multinuclear solid-state Nuclear Magnetic Resonance (ssNMR). Perhaps counterintuitively, pressurization tends to increase the concentration of three-coordinated boron species (B(III) units) at the expense of fourcoordinated boron (B(IV) units). 23Na NMR spectra show a systematic shift toward higher frequencies in the pressurized glasses, consistent with shorter average Na−O distances. The results are consistently explained in terms of a breakage of Si−O−B4 linkages resulting in the
formation of nonbridging oxygen species. Pressure effects on the spectra are reversed by annealing the glasses at their respective glass transition temperatures.

DOI： 10.1021/acs.jpclett.3c00540

Synthesis of transparent polycrystalline jadeite under high pressure and temperature 査読

Mitsu K., Irifune T., Ohfuji H., Yamada A.

Journal of Mineralogical and Petrological Sciences 116 ( 4 ) 203 - 210 2021年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Mineralogical and Petrological Sciences

Attempts to synthesize transparent polycrystalline jadeite have been made by direct conversion from bulk glass at pressures 10–20 GPa and temperatures 900–1300 °C using Kawai–type multianvil apparatus. The grain size of jadeite tends to decrease with increasing pressure, but we failed to synthesize polycrystalline jadeite with grain sizes in nano–regime (<100 nm) and obtained the sample with the smallest average grain size of ~ 240 nm at 20 GPa and 1300 °C for 20 min. Polycrystalline jadeite of the minimum grain size exhibits high optical transparency with a transmittance of ~ 70% for a typical wavelength in the visible region. The highest Vickers hardness (Hv) of 14.2 GPa was observed for the polycrystalline jadeite sample with the minimum grain size of ~240 nm, which is about 7% higher than the hardness (Hv = 13.3 GPa) of the sample with the largest grain size of ~ 390 nm. Further increases in optical transparency and hardness of polycrystalline jadeite would be realized if we get nano–polycrystalline samples by optimizing pressure, temperature, heating duration, etc. of the ultrahigh–pressure synthesis experiment.

DOI： 10.2465/JMPS.210319

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Transition in deformation mechanism of aluminosilicate glass at high pressure and room temperature 査読

Osada K., Yamada A., Ohuchi T., Yoshida S., Matsuoka J.

Journal of the American Ceramic Society 103 ( 12 ) 6755 - 6763 2020年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the American Ceramic Society

Deformation experiments for 20(MgO or Na O)-20Al O -60SiO glasses were performed in simple shear geometry at 1.5-5 GPa and room temperature. An abrupt change in the thinning rate and the turning of the birefringence azimuth at a shear strain of γ = 1-2 indicate a transition of deformation mechanism from uniaxial compression aided by densification to shear flow in the glasses. The high-dense magnesium aluminosilicate glass showed strain softening controlled by the rearrangement of the tetrahedral network. On the other hand, low-dense sodium aluminosilicate glass deformed by packing-induced flow associated with densification and via the rearrangement of the tetrahedral network at lower and higher strains, respectively. The transition of the deformation mechanism was triggered by the limitations of the densification of the tetrahedral network. The difference of deformation mechanism brought about higher strain in magnesium aluminosilicate glass than sodium aluminosilicate glass at the same stress condition. Easiness of remarkable deformation, which relaxed residual stress, and high deformability contributed to the high ductility of the MgO-aluminosilicate glass. 2 2 3 2

DOI： 10.1111/jace.17429

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Pressure-induced variation of persistent luminescence characteristics in Y₃Al_5-xGa_xO₁₂:Ce³⁺–M³⁺ (M = Yb, and Cr) phosphors: opposite trend of trap depth for 4f and 3d metal ions 査読国際誌

Jumpei Ueda, Masaya Harada, Shun Miyano, Akihiro Yamada and Setsuhisa Tanabe

Physical Chemistry Chemical Physics 22 19502 - 19511 2020年8月

Investigation on the orientation of boron in anisotropic borosilicate glass

Ryoya Hashimoto, Kosei Osada, Takaharu Nishikawa, Akihiro Yamada, Hirona Yamagishi

MEMOIRS OF THE SR CENTER RITSUMEIKAN UNIVERSITY ( 22 ) 44 2020年5月

Thermoelastic properties of K_0.7Na_0.3AlSi₃O₈ hollandite and NaAlSi₂O₆ jadeite: Implication for the fate of the subducted continental crust in the deep mantle 査読

Gréaux S., Zhou Y., Kono Y., Yamada A., Higo Y., Irifune T.

Minerals 10 ( 3 ) 2020年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Minerals

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The thermoelastic properties of K0.7Na0.3AlSi3O8 hollandite and NaAlSi2O6 jadeite, synthesized from a (K, Na)-felspar (microcline), were investigated by a combination of in situ energy dispersive synchrotron X-ray radiation and multi-anvil techniques at high pressure (P) and temperature (T) up to 21 GPa and 1700 K. The second-order phase transformation was found to occur in hollandite at ~16 GPa from tetragonal I/4m (hollandite-I) to monoclinic I2/m (hollandite-II), which confirms the previous report that the incorporation of Na in the hollandite structure decreases the transformation pressure. Fitting the pressure–volume–temperature data to the Birch–Murnaghan equation of state yielded estimates of the thermoelastic parameters for jadeite as well as the K0.7Na0.3AlSi3O8 hollandite-I and-II phases, which indicate that the incorporation of Na is likely to decrease the bulk moduli of both hollandite phases. The obtained thermoelastic parameters were combined with those of other mantle minerals reported previously to estimate the density of continental materials along an average mantle geotherm. Based on our results, continental crust and sediment become, respectively, 11% and 15% denser than the pyrolitic mantle at pressure >10 GPa, suggesting that once pulled down to the critical depth of ~300 km, the continental portions of the slab can subduct further into the deep mantle, down to the lowermost part of the mantle transition region.

DOI： 10.3390/min10030261

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In-situ Raman measurements of Silicate glasses dring Vickers Indentation 査読国際誌

S. Yoshida, T.H. Nguyen, A. Yamada, J. Matsuoka

Materials Transactions 2019年8月

Local structure analysis of light elements in simulated waste glasses

Atsunobu Masuno, Akihiro Yamada, Yoshiyuki Miura, Toyonari Yaji

MEMOIRS OF THE SR CENTER RITSUMEIKAN UNIVERSITY ( 21 ) 47 2019年5月

Structural investigation of Mg and B polyhedra in high Mg-baring borosilicate glasses

Akihiro Yamada, Naohiro Yuji, Atsunobu Masuno, Kei Mitsuhara, Satoshi Yoshida, Toshiaki Ohta, Jun Matsuoka

MEMOIRS OF THE SR CENTER RITSUMEIKAN UNIVERSITY ( 21 ) 54 2019年5月

Micro-Photoelastic Evaluation of Indentation-Induced Stress in Glass 査読国際誌

K. Asai, S. Yoshida, A. Yamada, J. Matsuoka, A. Errapart, Charles R. Kurkjian

Materials Transactions 2019年1月

Sound velocity of CaSiO₃ perovskite suggests the presence of basaltic crust in the Earth’s lower mantle 査読国際誌

Steeve Gréaux, Tetsuo Irifune, Yuji Higo, Yoshinori Tange, Takeshi Arimoto, Zhaodong Liu, Akihiro Yamada

Nature 565 218 - 221 2019年1月

Density variations of Cr-rich garnets in the upper mantle inferred from the elasticity of uvarovite garnet 査読国際誌

Steeve Greaux, Akihiro Yamada

Comptes Rendus Geoscience 351 95 - 103 2018年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier

The thermoelastic parameters of Ca3Cr2Si3O12 uvarovite garnet were examined in situ at high pressure up to 13 GPa and high temperature up to 1100 K by synchrotron radiation energy-dispersive X-ray diffraction within a 6-6-type multi-anvil press apparatus.

DOI： 10.1016/j.crte.2018.09.012

In-situ observation of the structural change in MgO-B₂O₃-SiO₂ glass at high pressure and the permanent structural change 査読

Yamada A., Harada M., Masuno A., Yamanaka K., Higo Y., Yoshida S., Ohta T., Matsuoka J.

Journal of Non-Crystalline Solids 499 25 - 31 2018年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Non-Crystalline Solids

© 2018 Elsevier B.V. A 41.6MgO-27.1B2O3-31.2SiO2 glass was synthesized by container-less levitation method. B K-edge X-ray absorption near edge structure (XANES) spectroscopy was used to quantify the coordination of boron in the as-made glass, resulting in ~72% of boron in 3-fold coordination. Raman spectroscopy indicated that the glass structure includes depolymerized borate units, which are pyroborate (B2O54−) and ring and/or chain-type metaborate (B3O63−, (BO2O−)∞) groups. The structural changes in the glass under hydrostatic condition were investigated by high-pressure Raman spectroscopy within a diamond anvil cell at pressures up to 8.5 GPa. On the borate structure, metaborate groups decreased with pressure. In contrast, triborate groups, which include tetrahedrally coordinated boron and have a fully polymerized borate network, increased; suggesting that the coordination transformation of B and polymerization were induced via compression. However, the modification of the borate structure units seems to be reversible at least up to 8.5 GPa. As for the silicate network, Q0 and Q1 structures were responsible to compression. Specifically, Q0 could be replaced by Q1 with elevating pressure, which means that the silicate network becomes polymerized with pressure. Whereas, structure of glass samples recovered from the pressure higher than 5 GPa displayed depolymerized silicate network, as dissociation of Q2 to Q1. The observed structural changes in the silicate network implied a partial change of the coordination number of Si4+ ions, which can be enhanced by the presence of a modifier cation with high field strength such as Mg2+.

DOI： 10.1016/j.jnoncrysol.2018.07.002

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