Strain control of the Néel vector in Mn-based antiferromagnets

Abstract

Control of the Néel vector in antiferromagnetic (AFM) materials is one of the challenges preventing their use as active device components. Several methods have been investigated such as exchange bias, electric current, and spin injection, but little is known about strain-mediated anisotropy. This study of the AFM L10-type MnX alloys MnIr, MnRh, MnNi, MnPd, and MnPt shows that a small amount of strain effectively rotates the direction of the Néel vector by 90° for all of the materials. For MnIr, MnRh, MnNi, and MnPd, the Néel vector rotates within the basal plane. For MnPt, the Néel vector rotates from out-of-plane to in-plane under tensile strain. The effectiveness of strain control is quantified by a metric of efficiency and by direct calculation of the magnetostriction coefficients. The values of the magnetostriction coefficients are comparable with those from ferromagnetic materials. These results indicate that strain is a mechanism that can be exploited for control of the Néel vectors in this family of antiferromagnets.