Zintl-phase Eu2ZnSb2: A promising thermoelectric material with ultralow thermal conductivity

Chen Chen; Wenhua Xue; Shan Li; Zongwei Zhang; Xiaofang Li; Xinyu Wang; Yijie Liu; Jiehe Sui; Xingjun Liu; Feng Cao; Zhifeng Ren; Ching-Wu Chu; Yumei Wang; Qian Zhang

doi:10.1073/pnas.1819157116

Zintl-phase Eu₂ZnSb₂: A promising thermoelectric material with ultralow thermal conductivity

Proc Natl Acad Sci U S A. 2019 Feb 19;116(8):2831-2836. doi: 10.1073/pnas.1819157116. Epub 2019 Feb 4.

Authors

Chen Chen^{1

2}, Wenhua Xue³, Shan Li^{1

2}, Zongwei Zhang^{1

2}, Xiaofang Li^{1

2}, Xinyu Wang^{1

2}, Yijie Liu⁴, Jiehe Sui⁵, Xingjun Liu^{1

2

5}, Feng Cao⁴, Zhifeng Ren⁶, Ching-Wu Chu⁷, Yumei Wang⁸, Qian Zhang^{9

2}

Affiliations

¹ Department of Materials Science and Engineering, Harbin Institute of Technology, 518055 Shenzhen, People's Republic of China.
² Institute of Materials Genome & Big Data, Harbin Institute of Technology, 518055 Shenzhen, People's Republic of China.
³ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing, People's Republic of China.
⁴ School of Science, Harbin Institute of Technology, 518055 Shenzhen, People's Republic of China.
⁵ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, 150001 Harbin, People's Republic of China.
⁶ Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204.
⁷ Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 cwchu@uh.edu wangym@iphy.ac.cn zhangqf@hit.edu.cn.
⁸ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing, People's Republic of China; cwchu@uh.edu wangym@iphy.ac.cn zhangqf@hit.edu.cn.
⁹ Department of Materials Science and Engineering, Harbin Institute of Technology, 518055 Shenzhen, People's Republic of China; cwchu@uh.edu wangym@iphy.ac.cn zhangqf@hit.edu.cn.

Abstract

Zintl compounds are considered to be potential thermoelectric materials due to their "phonon glass electron crystal" (PGEC) structure. A promising Zintl-phase thermoelectric material, 2-1-2-type Eu₂ZnSb₂ (P6₃/mmc), was prepared and investigated. The extremely low lattice thermal conductivity is attributed to the external Eu atomic layers inserted in the [Zn₂Sb₂]^2- network in the structure of 1-2-2-type EuZn₂Sb₂ [Formula: see text], as well as the abundant inversion domain boundary. By regulating the Zn deficiency, the electrical properties are significantly enhanced, and the maximum ZT value reaches ∼1.0 at 823 K for Eu₂Zn_0.98Sb₂ Our discovery provides a class of Zintl thermoelectric materials applicable in the medium-temperature range.

Keywords: Eu2ZnSb2; Zintl phase; low thermal conductivity; thermoelectric properties.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't