Strain-engineered high-temperature ferromagnetic Oxygen-substituted NaMnF3 from first principles

TL;DR

This study uses first-principles calculations to show that oxygen substitution and biaxial strain can turn NaMnF3 into a high-temperature ferromagnet suitable for spintronics.

Contribution

It reveals how oxygen substitution and strain induce a transition to high-temperature ferromagnetism in NaMnF3, expanding its potential applications.

Findings

Oxygen octahedron causes transition to half-metallic ferromagnet

Tensile strain can raise Curie temperature to room temperature

Exchange interactions are influenced by Jahn-Teller and rotation distortions

Abstract

Using first-principles calculations, we investigated the magnetic, electronic, and structural properties of oxygen-substituted NaMnF3 (NaMnF1.5O1.5) with in-plane biaxial strain. For simplicity, a structure containing an oxygen octahedron is used to explore the underlying physical mechanism. We found that the oxygen octahedron induces a transition from an insulating antiferromagnet to a high-temperature half-metallic ferromagnet. More importantly, the Curie temperature can be significantly enhanced and even might reach room temperature by applying tensile strain. The changing trends of exchange coupling constants with the increasing biaxial tensile strain can be attributed to the cooperative effects of Jahn-Teller distortion and rotation distortion. It is expected that these findings can enrich the versatility of NaMnF3 and make it a promising candidate for spintronic applications.