A Dual Role by Incorporation of Magnesium in YbZn(2)Sb(2)Zintl Phase for Enhanced Thermoelectric Performance
ADVANCED ENERGY MATERIALS(2020)
摘要
1-2-2-type Zintl phase compounds have promising thermoelectric properties because of their complex crystal structures and multiple valence-band structures. In this work, a series of single phase (Yb0.9Mg0.1)MgxZn2-xSb2(x= 0, 0.2, 0.4, 0.6, 0.8, and 1) compounds are prepared by alloying YbZn(2)Sb(2)with 10 at% MgZn(2)Sb(2)and different amounts of YbMg2Sb2. The incorporation of Mg at the Yb site, as well as at the Zn site, not only leads to an effective orbital alignment confirmed by the dramatically enhanced density of states effective mass and Seebeck coefficients, but also increases the point defect scattering, contributing to a low lattice thermal conductivity approximate to 0.54 W m(-1)K(-1)at 773 K. Combined with the optimization of the carrier concentration by Ag doping at the Zn site, a highestZTvalue approximate to 1.5 at 773 K is achieved in (Yb0.9Mg0.1)Mg0.8Zn1.2Ag0.002Sb2, which is higher than that of all the previously reported 1-2-2-type Zintl phase compounds.
更多查看译文
关键词
(Yb0,9Mg0,1)MgxZn2-xSb2,Ag doping,orbital alignment,thermoelectric,Zintl phase
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络