Anomalous Anisotropic Magnetoresistance of Antiferromagnetic Epitaxial Bimetallic Films: Mn₂Au and Mn₂Au/Fe Bilayers

Recently intensive efforts have been devoted to the emerging field of antiferromagnetic (AFM) spintronics, where ferromagnetic electrodes are substituted by antiferromagnets. This study investigates the anisotropic magnetoresistance (AMR) of epitaxial tetragonal antiferromagnetic bimetallic films: Mn₂Au and Mn₂Au/Fe bilayers. An anomalous AMR effect with additional peaks is observed. This study theoretically and experimentally demonstrates that the AFM spins of Mn₂Au can be viewed and controlled at room temperature, and this is achievable with a notably relatively small magnetic field of 200 mT. Strong hybridization between Au and Mn, and strong modification of the intrinsic quadratic anisotropy of Mn₂Au from interfacial biquadratic anisotropy result in an additional anomalous AMR component of 1%. The findings suggest that Mn₂Au films can be used in room temperature antiferromagnetic spintronics.