Giant thermoelectric power factor anisotropy in PtSb$_{1.4}$Sn$_{0.6}$

TL;DR

This paper reports a new phase of PtSb$_{1.4}$Sn$_{0.6}$ with giant anisotropy in thermoelectric power factor, mainly due to anisotropic Seebeck coefficients, highlighting significant directional dependence in its thermoelectric properties.

Contribution

The study introduces a new orthorhombic phase of PtSb$_{1.4}$Sn$_{0.6}$ with unprecedented anisotropic thermoelectric power factor, expanding understanding of directional thermoelectric behavior in this material class.

Findings

Giant anisotropy in thermoelectric power factor observed

Anisotropic Seebeck coefficients cause directional differences

New phase differs from cubic PtSb$_2$ and PtSn$_2$

Abstract

We report giant anisotropy in thermoelectric power factor ($S^2\sigma$) of marcasite structure-type PtSb$_{1.4}$Sn$_{0.6}$. PtSb$_{1.4}$Sn$_{0.6}$, synthesized using ambient pressure flux growth method upon mixing Sb and Sn on the same atomic site, is a new phase different from both PtSb$_2$ and PtSn$_2$ that crystallize in the cubic $Pa\bar{3}$ pyrite and $Fm\bar{3}m$ fluorite unit cell symmetry, respectively. Giant difference in $S^2\sigma$ for heat flow applied along different principal directions of the orthorhombic unit cell mostly stems from anisotropic Seebeck coefficients.