First principles investigation of magnetocrystalline anisotropy at the L2$_1$ Full Heusler|MgO interfaces and tunnel junctions

TL;DR

This study uses first principles calculations to analyze magnetocrystalline anisotropy at Heusler alloy|MgO interfaces, revealing how atomic termination influences magnetic orientation and identifying the orbital contributions responsible.

Contribution

It provides detailed atomic-level insights into the origin of magnetic anisotropy at Heusler|MgO interfaces, highlighting the role of atomic termination and orbital contributions.

Findings

Co$_{2}$FeAl|$MgO$ interfaces show perpendicular anisotropy with Co termination.

FeAl termination results in in-plane anisotropy.

Atomic orbital analysis links perpendicular anisotropy to Co out-of-plane orbitals.

Abstract

Magnetocrystalline anisotropy at Heusler alloy$|$MgO interfaces have been studied using first principles calculations. It is found that Co terminated Co$_{2}$FeAl$|$MgO interfaces show perpendicular magnetic anisotropy up to 1.31 mJ/m$^2$, while those with FeAl termination exhibit in-plane magnetic anisotropy. Atomic layer resolved analysis indicates that the origin of perpendicular magnetic anisotropy in Co$_{2}$FeAl$|$MgO interfaces can be attributed to the out-of-plane orbital contributions of interfacial Co atoms. At the same time, Co$_{2}$MnGe and Co$_{2}$MnSi interfaced with MgO tend to favor in-plane magnetic anisotropy for all terminations.