First-principles study of structural, electronic and magnetic properties at the \ce{(0001)Cr2O3-(111)Pt} interface

TL;DR

This study uses first-principles calculations to explore the structural, electronic, and magnetic properties of the a0Cr2O3-Pta0 interface, revealing electron accumulation, magnetic moment reversal, and proximity effects relevant for spintronic applications.

Contribution

It provides detailed insights into the interface properties of a0Cr2O3-Pta0 heterostructures, including the lowest energy alignment and magnetic phenomena, advancing understanding for spintronic device development.

Findings

Electron accumulation at the interface.

Reversal of Cr magnetic moments near Pt.

Magnetic proximity effect in the first three Pt layers.

Abstract

We perform first-principles density functional calculations to elucidate structural, electronic and magnetic properties at the interface of \ce{(0001)Cr2O3-(111)Pt} bilayers. This investigation is motivated by the fact that, despite the promise of \ce{Cr2O3-Pt} heterostructures in a variety of antiferromagnetic spintronic applications, many key structural, electronic, and magnetic properties at the \ce{Cr2O3-Pt} interface are poorly understood. We first analyze all inequivalent lateral interface alignments to determine the lowest energy interfacial structure. For all lateral alignments including the lowest-energy one, we observe an accumulation of electrons at the interface between \ce{Cr2O3} and Pt. We find an unexpected reversal of the magnetic moments of the interface Cr ions in the presence of Pt compared to surface Cr moments in vacuum-terminated \ce{(0001)Cr2O3}. We also find that the heterostructure exhibits a magnetic proximity effect in the first three Pt layers at the interface with \ce{Cr2O3}, providing a mechanism by which the anomalous Hall effect can occur in \ce{(0001)Cr2O3-(111)Pt} bilayers. Our results provide the basis for a more nuanced interpretation of magnetotransport experiments on \ce{(0001)Cr2O3-(111)Pt} bilayers and should inform future development of improved antiferromagnetic spintronic devices based on the \ce{Cr2O3-Pt} material system.