Anomalous Hall effect in the noncollinear antiferromagnetic antiperovskite Mn3Ni1-xCux N

We report the anomalous Hall effect (AHE) in antiperovskite Mn3NiN with substantial doping of Cu on the Ni site (i.e., Mn3Ni1-xCuxN), which stabilizes a noncollinear antiferromagnetic (AFM) order compatible with the AHE. Observed on both sintered polycrystalline pieces and single crystalline films, the AHE does not scale with the net magnetization, contrary to the conventional ferromagnetic case. The existence of the AHE is explained through symmetry analysis based on the Γ4g AFM order in Cu doped Mn3NiN. Density functional theory calculations of the intrinsic contribution to the AHE reveal the nonvanishing Berry curvature in momentum space due to the noncollinear magnetic order. Combined with other attractive properties, the antiperovskite Mn3AN system offers great potential in AFM spintronics.