Cost effective synthesis of p-type Zn-doped MgAgSb by planetary ball-milling with enhanced thermoelectric properties
Yanyan Zheng1, Chengyan Liu1, Lei Miao1
1Guangxi Key Laboratory of Information Materials, Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology Guilin 541004 P. R. China miaolei@guet.edu.cn.
Abstract:
As promising candidates for the progress of low-temperature thermoelectric devices, MgAgSb-based thermoelectric materials have drawn a great deal of attention. However, due to complicated phase changes, high content of impurities and high volatilization of Mg, it is difficult to synthesize pure phase MgAgSb-based thermoelectric materials via conventional methods. Here, MgAgSb alloy was successfully synthesized by a combination of common planetary ball milling and spark plasma sintering. Furthermore, the introduction of Zn improved the purity of alloys, leading to optimization of the electrical transport properties. As a result, the power factor was improved from 1087 μW m-1 K-2 for MgAg0.9Sb0.95 to 1394 μW m-1 K-2 for Mg0.97Zn0.03Ag0.9Sb0.95 at 473 K, and the ZT reached ∼0.7 at 473 K. These results suggest that MgAgSb-based thermoelectric materials have a good thermoelectric application potential and this study can be used as guidance for the synthesis and performance improvement of other thermoelectric materials. Our synthesis route sets forth a new avenue for accelerating commercial applications of MgAgSb-based thermoelectric power generation or refrigeration.
