Stability and thermoelectric properties of transition metal silicides from first principles calculations

TL;DR

This study uses first-principles calculations to analyze the stability and electronic properties of transition metal silicides, focusing on their potential for high-temperature thermoelectric applications, especially W5Si3 and Ta5Si3.

Contribution

It provides a detailed ab-initio analysis of the stability and thermoelectric properties of M5Si3 silicides, highlighting their potential and limitations for high-temperature thermoelectric use.

Findings

W5Si3 has a relatively large thermopower.

Ta5Si3 is stable up to about 2000°C.

W5Si3's thermopower may be insufficient for practical thermoelectric applications.

Abstract

We report an ab-initio study of the stability and electronic properties of transition metal silicides in order to study their potential for high temperature thermoelectric applications. We focus on the family M5Si3 (M = Ta, W) which is stable up to about 2000 {\deg}C. We first investigate the structural stability of the two compounds and then determine the thermopower of the equilibrium structure using the electronic density of states and Mott's law. We find that W5Si3 has a relatively large thermopower but probably not sufficient enough for thermoelectric applications.