Papers - YAMAMOTO Takahisa

Microstructure analysis for zirconium oxynitrides formed in 8 mol% yttria-doped zirconia by a flash event under a direct current electric field in an ambient atmosphere Reviewed

S. Sakamoto, A. Kodaira, T. Tokunaga, N. Morisaki, K. Kobayashi, T. Yamamoto

Journal of the European Ceramic Society   Vol. 45 ( 7 ) page： 117265   2025.7

　More details

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

DOI： 10.1016/j.jeurceramsoc.2025.117265

Healing behavior of microcracks on the surface of yttria-stabilized polycrystals using an ultrafast high-temperature sintering method Reviewed

T. Sato, A. Kodaira, T. Tokunaga, K. Morita, T. Yamamoto

Ceramics International   Vol. 51 ( 4 ) page： 4178 - 4184   2025.2

　More details

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

DOI： 10.1016/j.ceramint.2024.11.394

Spectrally Narrow Blue-Light Emission from Nonstoichiometric AgGaS2 Quantum Dots for Application to Light-Emitting Diodes Invited Reviewed

M. Tozawa, S. Ofuji, M. Tanaka, K. Akiyoshi, T. Kameyama, T. Yamamoto, G. Motomura, Y. Fujisaki, T. Uematsu, S. Kuwabata, T. Torimoto

ACS Applied Materials and Interfaces   Vol. 16   page： 68169 - 68180   2024.11

　More details

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

DOI： 10.1021/acsami.4c13987

Variation of (001) surface structures of strontium titanate single crystals caused by flash event under direct/alternative current electric fields Reviewed

Y. Katsuyama, S. Kayukawa, T. Tokunaga, S. Kobayashi, S. Hidaka, A. Nakamura, T. Yamamoto

Ceramics International   Vol. 50   page： 37366 - 37372   2024.10

　More details

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

DOI： https://doi.org/10.1016/j.ceramint.2024.05.055

Microstructural analysis of flash-healed Vickers-indented microcracks near positive/negative electrodes on the (001) surface of cubic zirconia single crystals under direct current electric fields Reviewed

S. Kayukawa, Y. Katsuyama, A. Kodaira, T. Tokunaga, K. Morita, T. Yamamoto

Ceramics International   Vol. 50   page： 37348 - 37355   2024.10

　More details

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

DOI： https://doi.org/10.1016/j.ceramint.2024.04.251

Highly c-axis-oriented apatite-type lanthanum silicate thin films fabricated by magnetron sputtering under bias Reviewed

S. Hidaka, K. Takagi, T. Yamamoto

Materials Chemistry and Physics   Vol. 326   page： 129852   2024.8

　More details

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

DOI： https://doi.org/10.1016/j.matchemphys.2024.129852

Variation of surface morphology of material uplift near flash-healed Vickers indents under direct-current electric field in cubic zirconia single crystals Reviewed

S. Kayukawa, Y. Katsuyama, T. Tokunaga, T. Yamamoto

Journal of the Ceramic Society of Japan   Vol. 132 ( 8 ) page： 528 - 531   2024.8

　More details

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

DOI： https://doi.org/10.2109/jcersj2.24036

Pulsed laser deposition and structural analysis of Ba2Ti6O13 epitaxial thin film on the (210) surface of SrTiO3 single crystal Reviewed

R. Kono, K. Hieda, T. Tokunaga, R. Tamura, R. Masamura, Y. Hikita, K. Kano, T. Yamamoto

Applied Physics Express   Vol. 17   page： 075503   2024.7

　More details

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

DOI： https://doi.org/10.35848/1882-0786/ad605d

The use of He buffer gas for moderating the plume kinetic energy during Nd:YAG-PLD growth of EuXY2-XO3 phosphor films Reviewed

S. Suzuki, T. Dazai, T. Tokunaga, T. Yamamoto, R. Katoh, M. Lippmaa, R. Takahashi

Journal of Applied Physics   Vol. 135   page： 195302   2024.5

　More details

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

DOI： https://doi.org/10.1063/5.0196987

Topographical and morphological changes of the single-crystal (La0.3Sr0.7)(Al0.65Ta0.35)O3 (001) surface treated with high-purity deionized water Reviewed

Y. Tokuda, N. Nishikawa, T. Irimoto, Y. Katsuyama, S. Kobayashi, T. Tokunaga, T. Yamamoto

Surface and Interface Analysis   Vol. 56 ( 8 ) page： 564 - 572   2024.4

　More details

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

DOI： https://doi.org/10.1002/sia.7313

Optical and mechanical properties of rutile TiO2 subjected to AC flash processing Reviewed

Hiroshi Masuda, Tomoharu Tokunaga, Takahisa Yamamoto, Hidehiro Yoshida

Scripta Materialia   Vol. 246   page： 116088   2024.3

　More details

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

DOI： https://doi.org/10.1016/j.scriptamat.2024.116088

Non-uniformity of shrinkage rate as a function of current acceleration during flash event under voltage-to-current protocol in 8 mol %Y2O3-ZrO2 Reviewed

M. Seko, S. Inagaki, T. Tokunaga, T. Yamamoto

Journal of the Ceramic Society of Japan   Vol. 132 ( 3 ) page： 93 - 98   2024.3

　More details

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

DOI： 10.2109/jcersj2.23179

Variation of grain boundary dihedral angles caused by voltage-to-current-based flash treatment in fully stabilized yttria-doped zirconia polycrystals Reviewed

M. Seko, S. Kayukawa, S. Inagaki, T. Tokunaga, T. Yamamoto

Journal of the Ceramic Society of Japan   Vol. 132 ( 2 ) page： 63 - 67   2024.2

　More details

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

DOI： https://doi.org/10.2109/jcersj2.23170

Applying an alternating current to strontium titanate minimizes the change in oxidation state caused by flash sintering Reviewed

M. Seko, S. Inagaki, T. Tokunaga, S. Kobayashi, A. Nakamura, T. Yamamoto

Journal of the European Ceramic Society   Vol. 44   page： 2965 - 2971   2023.12

　More details

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

DOI： https://doi.org/10.1016/j.jeurceramsoc.2023.12.046

One-pot synthesis of Ag–In–Ga–S nanocrystals embedded in a Ga2O3 matrix and enhancement of band-edge emission by Na+ doping Reviewed

M. Tozawa, C. Miyamae, K. Akiyoshi, T. Kameyama, T. Yamamoto, G. Motomura, Y. Fujisaki, T. Uematsu, S. Kuwabata, T. Torimoto

Nanoscale Advances   Vol. 5   page： 7057 - 7066   2023.11

　More details

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

DOI： https://doi.org/10.1039/d3na00755c

Near-full compaction within only 30 min of total sintering time by shrinkage-rate-controlled flash sintering in 3 mol% Y2O3-doped ZrO2 polycrystal Reviewed

Yuki ISHINO, Ayu KODAIRA, Tomoharu TOKUNAGA, and Takahisa YAMAMOTO

Journal of the Ceramic Society of Japan   Vol. 131 ( 10 )   2023.10

　More details

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

StructuralDefectEffecton the ConcentrationQuenchingofTbxY2−xO3PhosphorThin Films Reviewed

Shizuka Suzuki, Takuro Dazai, Tomoharu Tokunaga, Takahisa Yamamoto, Ryuzi Katoh, Ryota Takahashi

J. Phys.Chem.C   Vol. 127   page： 9380 - 9387   2023.9

　More details

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

DOI： 10.1021/acs.jpcc.3c01679

Apparent Sintering Activation Energy Estimated by Master Sintering Curves for 8 mol% Y2O3 Doped ZrO2 Polycrystals during Shrinkage-Rate Controlled Flash Sintering Reviewed

Masao KOIKE, Ayu KODAIRA, Tomoharu TOKUNAGA, and Takahisa YAMAMOTO

Materials Transactions   Vol. 64 ( 9 ) page： 2315 - 2320   2023.9

　More details

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

DOI： 10.2320/matertrans.MT-M2023048

Improvements in Flash Sintering for Practical Application Reviewed

Takahisa YAMAMOTO

Materials Transactions   Vol. 64 ( 9 ) page： 2059 - 2068   2023.9

　More details

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

DOI： 10.2320/matertrans.MT-Y2023003

Hydrogarnet-Derived Porous Polyhedral Particles of SrFeO3-δ Perovskite Reviewed

H. Otaguro, T. Takeno, R. Sugimoto, S. Hosokawa, H. Akamatsu, T. Yamamoto, K. Nakanishi, K. Hayashi, G. Hasegawa

Chemistry Materials   Vol. 35   page： 6423 - 6436   2023.8

　More details

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

DOI： https://doi.org/10.1021/acs.chemmater.3c01150