Magnetocrystalline anisotropy of Fe and Co slabs and clusters on SrTiO$\_3$ by first-principles

TL;DR

This study uses first-principles calculations to analyze how SrTiO3 substrates influence the magnetocrystalline anisotropy of Fe and Co slabs and clusters, revealing substrate-induced effects that could impact magnetic storage applications.

Contribution

It provides new insights into substrate effects on MCA in Fe and Co nanostructures, highlighting the role of hybridization and interface interactions.

Findings

Fe films on SrTiO3 quench MCA

Co shows sign change in MCA from in-plane to out-of-plane

Small clusters exhibit enhanced MCA on SrTiO3

Abstract

In this work, we present a detailed theoretical investigation of the electronic and magnetic properties of ferromagnetic slabs and clusters deposited on SrTiO$\_3$ via first-principles, with a particular emphasis on the magneto-crystalline anisotropy (MCA). We found that in the case of Fe films deposited on SrTiO$\_3$ the effect of the interface is to quench the MCA whereas for Cobalt we observe a change of sign of the MCA from in-plane to out-of-plane as compared to the free surface. We also find a strong enhancement of MCA for small clusters upon deposition on a SrTiO$\_3$ substrate. The hybridization between the substrate and the $d$-orbitals of the cluster extending in-plane for Fe and out-of-plane for Co is at the origin of this enhancement of MCA. As a consequence, we predict that the Fe nanocrystals (even rather small) should be magnetically stable and are thus good potential candidates for magnetic storage devices.