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  • Novel insights into lattice thermal transport in nanocrystalline Mg 3 Sb 2 from first principles: the crucial role of higher-order phonon scattering
Title: Novel insights into lattice thermal transport in nanocrystalline Mg 3 Sb 2 from first principles: the crucial role of higher-order phonon scattering
Zintl phase Mg 3 Sb 2 , which has ultra-low thermal conductivity, is a promising anisotropic thermoelectric material. It is worth noting that the prediction and experiment value of lattice thermal conductivity ( κ ) maintain a remarkable difference, troubling the development and application. Thus, we firstly included the four-phonon scattering processes effect and performed the Peierls–Boltzmann transport equation (PBTE) combined with the first-principles lattice dynamics to study the lattice thermal transport in Mg 3 Sb 2 . The results showed that our theoretically predicted κ is consistent with the experimentally measured, breaking through the limitations of the traditional calculation methods. The prominent four-phonon scatterings decreased phonon lifetime, leading to the κ of Mg 3 Sb 2 at 300 K from 2.45 (2.58) W m −1 K −1 to 1.94 (2.19) W m −1 K −1 along the in (cross)-plane directions, respectively, and calculation accuracy increased by 20%. This study successfully explains the lattice thermal transport behind mechanism in Mg 3 Sb 2 and implies guidance to advance the prediction accuracy of thermoelectric materials.  more » « less
Award ID(s):
2030128 1905775
PAR ID:
10358938
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
24
Issue:
35
ISSN:
1463-9076
Page Range / eLocation ID:
20891 to 20900
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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