Theoretical Study of Thermopower Behavior of LaFeO$_{3}$ Compound in High Temperature Region

TL;DR

This study combines ab-initio calculations and Boltzmann transport theory to analyze the thermopower of LaFeO₃ at high temperatures, revealing large positive thermopower linked to hole effective mass.

Contribution

It provides a theoretical analysis of LaFeO₃'s thermopower behavior using advanced electronic structure calculations and transport modeling, aligning well with experimental data.

Findings

Large positive thermopower in LaFeO₃ from 300-1200 K

Holes have approximately four times the effective mass of electrons

Calculated energy gap closely matches experimental values

Abstract

The electronic structure and thermopower ($\alpha$) behavior of LaFeO$_{3}$ compound were investigated by combining the ab-initio electronic structures and Boltzmann transport calculations. LSDA plus Hubbard U (U = 5 eV) calculation on G-type anti-ferromagnetic (AFM) configuration gives an energy gap of $\sim$2 eV, which is very close to the experimentally reported energy gap. The calculated values of effective mass of holes (m$^{*}$$_{h}$) in valance band (VB) are found $\sim$4 times that of the effective mass of electrons (m$^{*}$$_{e}$) in conduction band (CB). The large effective masses of holes are responsible for the large and positive thermopower exhibited by this compound. The calculated values of $\alpha$ using BoltzTraP code are found to be large and positive in the 300-1200 K temperature range, which is in agreement with the experimentally reported data.