文献类型：期刊文献

英文题名：Enhanced average thermoelectric properties of ntype Mg3Sb2 based materials by mixed-valence Ni doping

作者：Zhu, Wenyan[1]; Zheng, Pingping[1]; Shao, Yaoming[1]; Fang, Wenqiang[1]; Wu, Haifei[2]; Si, Jianxiao[1]

机构：[1] Department of Physics, Zhejiang Normal University, Jinhua, 321004, China; [2] Department of Physics, Shaoxing University, Shaoxing, 312000, China

年份：2022

卷号：924

外文期刊名：Journal of Alloys and Compounds

收录：EI(收录号：20223212544114)、Scopus(收录号：2-s2.0-85135389989)

语种：英文

外文关键词：Antimony compounds - Crystal lattices - Hot pressing - Magnesium compounds - Nickel - Thermal conductivity - Thermoelectric equipment

外文摘要：Due to their high band degeneracy and intrinsic low lattice thermal conductivity, n-type Mg3Sb2-based thermoelectric materials have drawn a lot of attention in thermoelectric applications in recent years. By using simple and efficient fast induction melting and hot pressing, the n-type Mg3.5?xNixSbBi0.96Te0.04 (x = 0, 0.015, 0.02, 0.03, 0.04, 0.05, and 0.06) samples have been successfully synthesized. The structure of Mg3.5?xNixSbBi0.96Te0.04 samples is examined, as well as their thermoelectric properties. The findings demonstrate that the mixed valence of Ni2+ and Ni3+ that occupied distinct Mg sites occurred as the Ni doping level grew in the Mg3.5?xNixSbBi0.96Te0.04 samples. The trivalent Ni3+ increases carrier concentrations dramatically, while the divalent Ni2+ increases the effective mass. The mixed valence of Ni causes lattice disorder, which enhances phonon scattering and reduces lattice thermal conductivity. As a result, the Mg3.485Ni0.015SbBi0.96Te0.04 sample has a high ZT value of 1.58 at 743 K and an average ZT value of 1.22 from 323 to 743 K. This work suggests that the mixed valence of cationic dopant effectively improve the thermoelectric performance of n-type Mg3Sb2-based compounds. ? 2022 Elsevier B.V.