Strain control of the Néel vector in L1₀-type Mn-based antiferromagnetic materials: a first principles study

Mn-based antiferromagnetically ordered L1₀-type crystals such as MnIr, MnRh, MnNi, MnPd, and MnPt are of interest for possible electronic or spintronic applications. We used first-principles calculations to study the effect of strain on the magnetic anisotropy of those materials. The strain is applied along one axis (a) of the basal plane, and the structure and lattice vectors in the other two directions (b,c) are fully relaxed. We found that by applying strain, the direction of the Néel vector can be rotated by 90° for all materials. For MnIr, MnRh, MnNi, and MnPd, the Néel vector rotates within the basal plane. The sign of the effect, whether compression along the a-axis leads to a parallel or perpendicular Néel vector, depends on the specific material. MnPt is unique among this material family, since, at zero strain, its Néel vector lies along the c-axis, and strain along the a-axis rotates it into the basal plane.