First-principles predictions of low-energy phases of multiferroic BiFeO3

TL;DR

This study employs first-principles calculations to systematically identify and analyze low-energy phases of multiferroic BiFeO3, revealing numerous local minima and structural variants relevant to experiments and theoretical models.

Contribution

It provides a comprehensive first-principles exploration of potential stable and metastable phases of BiFeO3, expanding understanding of its structural diversity.

Findings

Discovered many local minima within 100 meV/f.u. of the ground state.

Identified a variety of low-symmetry structures.

Discussed implications for experimental phases and theoretical models.

Abstract

We used first-principles methods to perform a systematic search for potentially-stable phases of multiferroic BiFeO3. We considered a simulation cell compatible with the atomic distortions that are most common among perovskite oxides, and found a large number of local minima of the energy within 100 meV/f.u. of the ferroelectric ground state. We discuss the variety of low-symmetry structures discovered, as well as the implications of these findings as regards current experimental (e.g., on thin films displaying {\em super-tetragonal} phases) and theoretical (on models for BiFeO3's structural phase transitions) work on this compound.