著者

鄭 東 田中 三郎 宮崎 康次 高尻 雅之

出版者

一般社団法人日本機械学会

雑誌

マイクロ・ナノ工学シンポジウム

巻号頁・発行日

vol.2013, no.5, pp.63-64, 2013-11-04

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We investigated strain and grain size effects on the thermal transport of nanocrystalline bismuth antimony telluride thin films using both experimental studies and modeling. The fabricated thin films exhibited the average grain sizes of 30 < d < 100 nm, and the strain of-0.8% < ε < -1.4% in the c-axis direction whereas that of a-b-axis direction was constant at 1.7%. The thermal conductivities were measured using a 3ω method at room temperature. We calculated the lattice thermal conductivity using a simplified phonon transport model that accounts for the strain effect based on Christoffel equation and Lennard-Jones potential, and the grain size effect based on the full distribution of mean free paths. The theoretical calculation was largely in good agreement with our experimental results, and the detailed results will be discussed in the Symposium.

著者

高尻 雅之 白川 寿照 宮崎 康次 塚本 寛

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.72, no.723, pp.1793-1798, 2006-11-25

参考文献数

27

被引用文献数

8

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n-type bismuth-telluride thin films are fabricated by flash evaporation method. Effects of hydrogen annealing on the thin films are investigated for potential application in micro thermoelectric devices. The thin films are grown up to 1 μm on a glass substrate by flash evaporation method. The hydrogen annealing is carried out in the temperature range between 200-350℃ on an atmospheric pressure. The electrical resistivity and Seebeck coefficient are measured at room temperature. Both the electrical resistivity and Seebeck coefficient are improved by the treatment of hydrogen annealing, then the power factor of the n-type bismuth-telluride thin film reaches 8.8μW・cm^&lt;-1&gt;・K^2 at annealing temperature of 350℃. The structure of the thin films, which is composition and crystallinity, is studied by electron probe micro analyzer and X-ray diffraction pattern, respectively. The composition of bismuth-telluride thin films is relativity constant until higher annealing temperature. The X-ray diffraction patterns indicate that the crystallinity of the thin films is improved as higher annealing temperature.