Thermoelectric Transport Properties of RyFe3NiSb12（R=Ba,Nd and Yb）
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2014年第11期
论文作者：Ruiheng Liu Jiong Yang Wenqing Zhang Lidong Chen
文章页码：1134 - 1140
摘 要：To evaluate the influence of Ni substitution on electrical transport properties, the thermoelectric transport properties of the p-type skutterudites R y Fe3 Ni Sb12（R = Ba, Nd and Yb） are systematically investigated from2.5 K to 800 K. By carefully modifying the filling fractions of the three fillers, Ba, Nd and Yb, the carrier concentration is precisely adjusted, which changes proportionally to the nominal value calculated by valence counting rule. The carrier concentration dependences of mobility and Seebeck coefficient represent two band contribution in the valence band, and the optimized carrier concentration for thermoelectric performance is between（5-9） 1020cm3. The lattice thermal conductivity of samples filled with rare-earth elements（Nd and Yb） are significantly lower as compared to Ba-filled, due to the lower resonant frequency and partial filling. Compared with Co substitution, Ni substitution tends to close the band gap, which results in heavier bipolar diffusion at high temperature for R y Fe3 Ni Sb12. However, due to the enhancement of the density of state, when the carrier concentrations are similar, R y Fe3 Ni Sb12possess higher thermal power and thus higher power factor than R y Fe2Co2Sb12 in the lower temperature range. A ZT value of 0.73 is obtained for Yb0.77Fe3 Ni Sb12at 600 K.
Ruiheng Liu1，Jiong Yang3，Wenqing Zhang1，Lidong Chen1
1. CAS Key Laboratory for Energy-conversion Materials,Shanghai Institute of Ceramics,Chinese Academy of Sciences3. Department of Materials Science & Engineering,University of Washington
摘 要：To evaluate the influence of Ni substitution on electrical transport properties, the thermoelectric transport properties of the p-type skutterudites R y Fe3 Ni Sb12（R = Ba, Nd and Yb） are systematically investigated from2.5 K to 800 K. By carefully modifying the filling fractions of the three fillers, Ba, Nd and Yb, the carrier concentration is precisely adjusted, which changes proportionally to the nominal value calculated by valence counting rule. The carrier concentration dependences of mobility and Seebeck coefficient represent two band contribution in the valence band, and the optimized carrier concentration for thermoelectric performance is between（5-9） 1020cm3. The lattice thermal conductivity of samples filled with rare-earth elements（Nd and Yb） are significantly lower as compared to Ba-filled, due to the lower resonant frequency and partial filling. Compared with Co substitution, Ni substitution tends to close the band gap, which results in heavier bipolar diffusion at high temperature for R y Fe3 Ni Sb12. However, due to the enhancement of the density of state, when the carrier concentrations are similar, R y Fe3 Ni Sb12possess higher thermal power and thus higher power factor than R y Fe2Co2Sb12 in the lower temperature range. A ZT value of 0.73 is obtained for Yb0.77Fe3 Ni Sb12at 600 K.
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