研究者詳細 - 旭　良司

論文 - 旭　良司

分割表示 170 件中 101 - 120 件目／全件表示 >>

1506 ハイブリッド量子古典シミュレーション : オーダーN型実空間DFT法の開発とLiグラファイト層間化合物への応用(OS15.固体物理/流体物理のマルチフィジックス/マルチスケール解析(2),OS・一般セッション講演)

大庭伸子, 尾形修司, 小林亮, 田村友幸, 旭良司

計算力学講演会講演論文集 2011 巻 ( 0 ) 頁： 481 - 482 2011年

906 フェーズフィールド法を用いた多結晶酸化物内リチウム拡散解析(OS9.フェーズフィールド法とその多様な展開(2),OS・一般セッション講演)

山川俊輔, 山崎久嗣, 小山敏幸, 旭良司

計算力学講演会講演論文集 2011 巻 ( 0 ) 頁： 296 - 297 2011年

Selected contributions from the 3rd Theory Meets Industry International Workshop, TMI2009 (Nagoya, Japan, 11-13 November 2009) PREFACE 査読有り

Tanaka Isao, Hafner Juergen, Wimmer Erich, Asahi Ryoji

JOURNAL OF PHYSICS-CONDENSED MATTER 22 巻 ( 38 ) 頁： 380301 2010年9月

Electronic Structure and Thermoelectric Properties of Al-Mn-Fe-Si Alloys 査読有り

Takeuchi T., Toyama Y., Hazama H., Asahi R.

JOURNAL OF ELECTRONIC MATERIALS 39 巻 ( 9 ) 頁： 1433 - 1438 2010年9月

Electronic structure and thermoelectric properties of Si<inf>2</inf>Ti-Type Al-(Mn, X)-Si (X = Cr, Fe) alloys 査読有り

Toyarna Y.

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals 74 巻 ( 9 ) 頁： 605 - 609 2010年9月

記述言語：英語掲載種別：研究論文（その他学術会議資料等）出版者・発行元：Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals

In order to make variation in thermoelectric properties of Si2Ti-type Al32Mn34Si34, which possesses a large magnitude of Seebeck coefficient exceeding 300 μV/K, we partially substituted Fe and Cr for Mn, and succeeded in decreasing the number of valence electrons by the latter. The large, positive Seebeck coefficient up to 330 μV/K was observed for Al32CrxMn34−xSi34 (1≤x≤2.5), which consists almost solely of the phase of Si2Ti-type structure. The increase of hole concentration with increasing Cr concentration was confirmed by the fact that the electrical resistivity was decreased with Cr concentration. The positive sign and the decrease of Seebeck coefficient with increasing Cr concentration also lend a support on this scenario. The largest ZT-value with the positive sign of Seebeck coefficient (p-type behavior) was obtained at Al32Cr2.5Mn31.5Si34, and the resulting ZT-value was twice as large as the largest ZT-value of the ternary compound Al33Mn34Si33 that possesses a p-type behavior.

DOI： 10.2320/jinstmet.74.605

Scopus

Electronic Structure and Thermoelectric Properties of Si2Ti-Type Al-(Mn, X)-Si (X = Cr, Fe) Alloys 査読有り

Toyama Yasuhiro, Hazama Hirofumi, Asahi Ryoji, Takeuchi Tsunehiro

JOURNAL OF THE JAPAN INSTITUTE OF METALS 74 巻 ( 9 ) 頁： 605 - 609 2010年9月

Study of Electronic Structure and Defect Formation in Ti1-x Ni1+x Sn Half-Heusler Alloys 査読有り

Hazama Hirofumi, Asahi Ryoji, Matsubara Masato, Takeuchi Tsunehiro

JOURNAL OF ELECTRONIC MATERIALS 39 巻 ( 9 ) 頁： 1549 - 1553 2010年9月

Thermoelectric Properties of Si2Ti-Type Al-Mn-Si Alloys 査読有り

Takeuchi Tsunehiro, Toyama Yasuhiro, Yamamoto Akio, Hazama Hirofumi, Asahi Ryoji

MATERIALS TRANSACTIONS 51 巻 ( 6 ) 頁： 1127 - 1135 2010年6月

記述言語：英語掲載種別：研究論文（その他学術会議資料等）出版者・発行元：Materials Transactions

By using the first principle band calculations, we identified that Si2Ti-type Al-Mn-Si C54-phase possesses an electronic structure suitable for the thermoelectric materials. The formation range of the Al-Mn-Si C54-phase was determined by preparing samples at a number of different compositions, and the samples solely consisting of the C54-phase were successfully obtained around Al:Mn:Si=1:1:1. The carrier concentration of the Al-Mn-Si C54-phase was controlled by the partial substitution of the constituent elements, and behaviors in electrical properties characteristic to n-type and p-type thermoelectric materials were alternatively observed for the samples of a larger electron concentration and a smaller electron concentration, respectively. The absolute value of the Seebeck coefficient |S| was found to exceed 300 μV/K for both n-type and p-type samples.

DOI： 10.2320/matertrans.M2010022

Web of Science

Scopus

Anomalies in the response of V, Nb, and Ta to tensile and shear loading: Ab initio density functional theory calculations 査読有り

Nagasako Naoyuki, Jahnatek Michal, Asahi Ryoji, Hafner Juergen

PHYSICAL REVIEW B 81 巻 ( 9 ) 2010年3月