Epitaxial strain control of hole-doping induced phases in a multiferroic Mott insulator Bi2FeCrO6

TL;DR

This study uses first-principles calculations to show how epitaxial strain combined with A-site hole doping in Bi2FeCrO6 can induce multiple phase transitions, potentially leading to novel functionalities in multiferroic materials.

Contribution

It demonstrates the control of structural, electronic, and magnetic phases in Bi2FeCrO6 through epitaxial strain and doping, revealing new pathways for material property tuning.

Findings

Epitaxial strain mitigates anti-site defects and reduces magnetization issues.

Strain and doping induce transitions such as half-metal to insulator, antipolar to polar, and magnetic order changes.

Prediction of a half-metallic polar phase with large magnetic moment.

Abstract

Epitaxial strain has been shown to drive structural phase transitions along with novel functionalities in perovskite-based thin-films. Aliovalent doping at the A-site can drive an insulator-to-metal and magnetic transitions in perovskites along with a variety of interesting structural and electronic phenomena. Using first-principles calculations, we demonstrate here, how coupling epitaxial strain with A-site hole doping in a multiferroic double perovskite, Bi2FeCrO6, could lead to mitigation of issues related to anti-site defects and lowered magnetisation in thin-films of the material. We also show that epitaxial strain can be used to manipulate the hole states created by doping to induce half-metal to insulator, antipolar to polar, antiferromagnetic to ferromagnetic, orbital ordering and charge ordering transitions. We also predict the formation of a half-metallic polar phase with a large magnetic moment which could be of immense fundamental and technological significance.