Ground state structure of BaFeO$_{3}$: Density Functional Theory Calculations

TL;DR

This study uses density functional theory to determine the most stable structure of BaFeO3, revealing its ferromagnetic and half-metallic properties across different phases, with implications for its magnetic behavior at room temperature.

Contribution

The paper provides a comprehensive DFT analysis of BaFeO3's ground state structure, magnetic coupling, and electronic properties, including the effects of Hubbard U corrections.

Findings

Cubic structure is most stable for BaFeO3.

All studied phases exhibit ferromagnetism.

BaFeO3 phases are half-metallic with integer magnetic moments.

Abstract

Using density functional theory calculations, the ground state structure of BaFeO$_3$ (BFO) is investigated with local spin density approximation (LSDA). Cubic, tetragonal, orthorhombic, and rhombohedral types BFO are considered to calculate the formation enthalpy. The formation enthalpies reveal that cubic is the most stable structure of BFO. Small energy difference between the cubic and tetragonal suggests a possible tetragonal BFO. Ferromagnetic(FM) and anitiferromagnetic (AFM) coupling between the Fe atoms show that all the striochmetric BFO are FM. The energy difference between FM and AFM shows room temperature ferromagnetism in cubic BFO in agreement with the experimental work. The LSDA calculated electronic structures are metallic in all studied crystallographic phases of BFO. Calculations including the Hubbard potential $U,i.e.$ LSDA+$U$, show that all phases of BFO are half-metallic consistent with the integer magnetic moments. The presence of half-metallicity is discussed in terms of electronic band structures of BFO.