Understanding and Designing the Spin-Driven Thermoelectrics

TL;DR

This paper explores the potential of spin degrees of freedom to enhance thermoelectric materials, presenting concepts, case studies, and design guidelines for spin-driven thermoelectrics to improve efficiency.

Contribution

It introduces the concept of spin-driven thermoelectrics, analyzes the role of spin-related phenomena, and provides design guidelines for high-performance materials.

Findings

Spin and heat current interplay can enhance thermopower.

Spin entropy and magnon effects can increase thermoelectric power factor.

MnTe exhibits significant spin-mediated thermoelectric properties.

Abstract

While the thermoelectric materials progress based on the engineering of electronic and phononic characteristics is reaching a plateau, adding the spin degree of freedom has the potential to open a new landscape for alternative thermoelectric materials. Here we present the concepts, current understanding, and guidelines for designing spin-driven thermoelectrics. We show that the interplay between the spin and heat currents in entropy transport via charge carriers can offer a strategic path to enhance the electronic thermopower. The classical antiferromagnetic semiconductor manganese telluride (MnTe) is chosen as the case study due to its significant spin-mediated thermoelectric properties. We show that although the spin-disorder scattering reduces the carrier mobility in magnetic materials, spin entropy, magnon, and paramagnon carrier drags can dominate over and significantly enhance the thermoelectric power factor and hence zT. Finally, several guidelines are drawn based on the current understandings for designing high-performance spin-driven thermoelectric materials.