Revealing the Defect-Dominated Electron Scattering in Mg3Sb2-Based Thermoelectric Materials

Jucai Jia; Yan Zhou; Xiaoxi Chen; Wenhua Xue; Hulei Yu; Jing Li; Shizhen Zhi; Chen Chen; Jian Wang; Shuaihang Hou; Xingjun Liu; Yumei Wang; Feng Cao; Yue Chen; Jun Mao; Qian Zhang

doi:10.34133/2022/9875329

Revealing the Defect-Dominated Electron Scattering in Mg₃Sb₂-Based Thermoelectric Materials

Research (Wash D C). 2022 Oct 14:2022:9875329. doi: 10.34133/2022/9875329. eCollection 2022.

Authors

Jucai Jia¹, Yan Zhou², Xiaoxi Chen³, Wenhua Xue^{1

4}, Hulei Yu⁵, Jing Li³, Shizhen Zhi¹, Chen Chen¹, Jian Wang⁶, Shuaihang Hou⁶, Xingjun Liu^{1

7}, Yumei Wang⁴, Feng Cao⁶, Yue Chen⁵, Jun Mao^{1

7}, Qian Zhang^{1

7}

Affiliations

¹ School of Materials Science and Engineering, and Institute of Materials Genome & Big Data, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
² Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK.
³ Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
⁴ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China.
⁵ Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
⁶ School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
⁷ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.

Abstract

The thermoelectric parameters are essentially governed by electron and phonon transport. Since the carrier scattering mechanism plays a decisive role in electron transport, it is of great significance for the electrical properties of thermoelectric materials. As a typical example, the defect-dominated carrier scattering mechanism can significantly impact the room-temperature electron mobility of n-type Mg₃Sb₂-based materials. However, the origin of such a defect scattering mechanism is still controversial. Herein, the existence of the Mg vacancies and Mg interstitials has been identified by synchrotron powder X-ray diffraction. The relationship among the point defects, chemical compositions, and synthesis conditions in Mg₃Sb₂-based materials has been revealed. By further introducing the point defects without affecting the grain size via neutron irradiation, the thermally activated electrical conductivity can be reproduced. Our results demonstrate that the point defects scattering of electrons is important in the n-type Mg₃Sb₂-based materials.