High-temperature thermoelectric properties of Nb-doped MNiSn (M = Ti, Zr) half-Heusler compound

被引：0

作者：

Muta, Hiroaki ^{[1
]}

Kanemitsu, Takanori ^{[1
]}

Kurosaki, Ken ^{[1
]}

Yamanaka, Shinsuke ^{[1
]}

机构：

[1] Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan

来源：

Journal of Alloys and Compounds | 2009年 / 469卷 / 1-2期

关键词：

The temperature dependence of electrical conductivity; Seebeck coefficient; Hall coefficient; and thermal conductivity of Nb-doped MNiSn (M = Ti; Zr) half-Heusler compounds were investigated at different temperature; ranging from room temperature to 1000 K. The power factor reached 4 × 10-3 Wm-1 K-2 above 600 K for both systems. The power factor for TiNiSn-based samples decreased above 700 K due to the narrower band gap. The Hall mobility was relatively small; however; estimated carrier effective mass was larger by one order of magnitude than that for conventional thermoelectric material. The thermal conductivity increased above 700 K due to the ambipolar diffusion effect. The ambipolar diffusion effect depended on the band gap width and the ratio of electron-hole conductivity. Heavy carrier-doping effectively suppressed the ambipolar diffusion effect; i.e. restrain the increase of thermal conductivity at high temperature. The maximum ZT value of 0.6 at 800 K was obtained for Zr0.98Nb0.02NiSn. © 2008 Elsevier B.V. All rights reserved;

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摘要：

Journal article (JA)

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页码：50 / 55