Enhanced thermoelectric properties of Co_1-x-yNi_x+ySb_3-xSn_x materials

Hong-quan Liu1),Sheng-nan Zhang2),Tie-jun Zhu2),Xin-bing Zhao2),Yi-jie Gu1),and Hong-zhi Cui1)1) College of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266510,China 2) State Key Laboratory of Silicon Materials,Development of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China

摘 要：Co1-x-yNix+ySb3-xSnx polycrystals were fabricated by vacuum melting combined with hot-press sintering.The effect of alloying on the thermoelectric properties of unfilled skutterudite Co1-xNixSb3-xSnx was investigated.A leap of electrical conductivity from the Co0.93Ni0.07Sb2.93Sn0.07 sample to the Co0.88Ni0.12Sb2.88Sn0.12 sample occurs during the measurement of electrical conductivity,indicating the adjustment of band structure by proper alloying.The results show that alloying enhances the power factor of the materials.On the basis of alloying,the thermoelectric properties of Co0.88Ni0.12Sb2.88Sn0.12 are improved by Ni-doping.The thermal conductivities of Ni-doping sam-ples have no reduction,but their power factors have obvious enhancement.The power factor of Co0.81Ni0.19Sb2.88Sn0.12 reaches 3.0 mWm-1-K-2 by Ni doping.The dimensionless thermoelectric figure of merit reaches 0.55 at 773 K for the unfilled Co0.81Ni0.19 Sb2.88Sn0.12.

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