Magnetic properties of La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunctions: chemically abrupt versus atomic intermixed interface

TL;DR

This study uses first-principles calculations to explore how interface chemistry affects magnetic ordering in La(0.67)Sr(0.33)MnO3/BiFeO3 heterojunctions, revealing that atomic intermixing promotes ferromagnetic Fe spin alignment.

Contribution

It demonstrates that cation intermixing at the heterojunction interface influences magnetic ordering, providing insights into experimental observations.

Findings

Chemically abrupt interface shows compensated Fe spins.

Intermixing favors ferromagnetic Fe spin order.

Exchange interaction energetics explain magnetic trends.

Abstract

Using first-principles density-functional calculations, we address the magnetic properties of the ferromagnet/antiferromagnet La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunctions, and investigate possible driving mechanisms for a ferromagnetic (FM) interfacial ordering of the Fe spins recently observed experimentally. We find that the chemically abrupt defect-free La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunction displays, as ground state, an ordering with compensated Fe spins. Cation Fe/Mn intermixing at the interface tends to favour, instead, a FM interfacial order of the Fe spins, coupled antiferromagnetically to the bulk La(0.67)Sr(0.33)MnO3 spins, as observed experimentally. Such trends are understood based on a model description of the energetics of the exchange interactions.