Disclosing antiferromagnetism in tetragonal Cr2O3 by electrical measurements

TL;DR

This study demonstrates antiferromagnetism in epitaxially grown tetragonal Cr2O3 ultrathin films up to 40 K through electrical measurements, revealing interface effects in a neighboring platinum layer.

Contribution

First experimental evidence of antiferromagnetism in tetragonal Cr2O3 via electrical measurements exploiting interface effects.

Findings

Antiferromagnetism observed up to 40 K in t-Cr2O3 films.

Magnetotransport affected by spin-Hall magnetoresistance and magnetic proximity.

Low-temperature resistance anomaly in Pt is not magnetic in origin.

Abstract

The tetragonal phase of chromium (III) oxide, although unstable in the bulk, can be synthesized in epitaxial heterostructures. The theoretical investigation by density functional theory predicts an antiferromagnetic ground state for this compound. We demonstrate experimentally antiferromagnetism up to 40 K in ultrathin films of t-Cr2O3 by electrical measurements exploiting interface effect within a neighboring ultrathin Pt layer. We show that magnetotransport in Pt is affected by both spin-Hall magnetoresistance and magnetic proximity effect while we exclude any role of magnetism for the low-temperature resistance anomaly observed in Pt.