Phase Boundary Mapping in ZrNiSn Half-Heusler for Enhanced Thermoelectric Performance

Xiaofang Li; Pengbo Yang; Yumei Wang; Zongwei Zhang; Dandan Qin; Wenhua Xue; Chen Chen; Yifang Huang; Xiaodong Xie; Xinyu Wang; Mujin Yang; Cuiping Wang; Feng Cao; Jiehe Sui; Xingjun Liu; Qian Zhang

doi:10.34133/2020/4630948

Phase Boundary Mapping in ZrNiSn Half-Heusler for Enhanced Thermoelectric Performance

Research (Wash D C). 2020 Jan 30:2020:4630948. doi: 10.34133/2020/4630948. eCollection 2020.

Authors

Xiaofang Li¹, Pengbo Yang¹, Yumei Wang², Zongwei Zhang¹, Dandan Qin³, Wenhua Xue², Chen Chen¹, Yifang Huang¹, Xiaodong Xie¹, Xinyu Wang¹, Mujin Yang¹, Cuiping Wang⁴, Feng Cao⁵, Jiehe Sui³, Xingjun Liu^{1

3}, Qian Zhang¹

Affiliations

¹ Department of Materials Science and Engineering, Institute of Materials Genome & Big Data, Harbin Institute of Technology, Shenzhen, Guangdong 518055, China.
² Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
³ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China.
⁴ Department of Materials Science and Engineering, Xiamen University, Xiamen, Fujian 361005, China.
⁵ Department of Science, Harbin Institute of Technology, Shenzhen, Guangdong 518055, China.

Abstract

The solubility range of interstitial Ni in the ZrNi_1+x Sn half-Heusler phase is a controversial issue, but it has an impact on the thermoelectric properties. In this study, two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973 K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni, Zr-Sn, and Ni-Sn. The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting. Solubilities of x < 0.07 at 973 K and x < 0.13 at 1173 K were clearly indicated. An intermediate-Heusler phase with a partly filled Ni void was observed, which is believed to be beneficial to the lowered lattice thermal conductivity. The highest ZT value~0.71 at 973 K was obtained for ZrNi_1.11Sn_1.04. The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.