Solid-State Janus Nanoprecipitation Enables Amorphous-Like Heat Conduction in Crystalline Mg3 Sb2 -Based Thermoelectric Materials

Rui Shu; Zhijia Han; Anna Elsukova; Yongbin Zhu; Peng Qin; Feng Jiang; Jun Lu; Per O Å Persson; Justinas Palisaitis; Arnaud le Febvrier; Wenqing Zhang; Oana Cojocaru-Mirédin; Yuan Yu; Per Eklund; Weishu Liu

doi:10.1002/advs.202202594

Solid-State Janus Nanoprecipitation Enables Amorphous-Like Heat Conduction in Crystalline Mg₃ Sb₂ -Based Thermoelectric Materials

Adv Sci (Weinh). 2022 Sep;9(25):e2202594. doi: 10.1002/advs.202202594. Epub 2022 Jul 18.

Authors

Rui Shu^{1

2}, Zhijia Han¹, Anna Elsukova², Yongbin Zhu¹, Peng Qin¹, Feng Jiang¹, Jun Lu², Per O Å Persson², Justinas Palisaitis², Arnaud le Febvrier², Wenqing Zhang³, Oana Cojocaru-Mirédin⁴, Yuan Yu⁴, Per Eklund², Weishu Liu^{1

5}

Affiliations

¹ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
² Thin Film Physics Division, Department of Physics Chemistry, and Biology (IFM), Linköping University, Linköping, SE-581 83, Sweden.
³ Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
⁴ I. Physikalisches Institut (IA), RWTH Aachen University, Sommerfeldstraße14, 52074, Aachen, Germany.
⁵ Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.

Abstract

Solid-state precipitation can be used to tailor material properties, ranging from ferromagnets and catalysts to mechanical strengthening and energy storage. Thermoelectric properties can be modified by precipitation to enhance phonon scattering while retaining charge-carrier transmission. Here, unconventional Janus-type nanoprecipitates are uncovered in Mg₃ Sb_1.5 Bi_0.5 formed by side-by-side Bi- and Ge-rich appendages, in contrast to separate nanoprecipitate formation. These Janus nanoprecipitates result from local comelting of Bi and Ge during sintering, enabling an amorphous-like lattice thermal conductivity. A precipitate size effect on phonon scattering is observed due to the balance between alloy-disorder and nanoprecipitate scattering. The thermoelectric figure-of-merit ZT reaches 0.6 near room temperature and 1.6 at 773 K. The Janus nanoprecipitation can be introduced into other materials and may act as a general property-tailoring mechanism.

Keywords: Janus nanoprecipitation; Mg3Sb2; atom probe tomography; low thermal conductivity; thermalelectrics.

Abstract

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