Anisotropic and spin Hall magnetoresistance in FeRh/Pt bilayers*

We have sputtered epitaxial films of BCC FeRh with thicknesses between 7.5-35 nm on (100) MgO, capped with 5-nm Pt. Magnetometry and magnetotransport measurements indicate a first-order transition from ferromagnetic to antiferromagnetic order below room temperature. We have structured lithographically the films into Hall bars and nano-wires, such that the current is directed along different crystalline orientations. The angular-dependent magnetoresistance of all devices is measured in both the ferromagnetic and antiferromagnetic phase, and there is evidence for both intrinsic anisotropic magnetoresistance as well as spin Hall magnetoresistance contributing to the measured signal. In the antiferromagnetic phase we measure drastically different angular signals depending on whether the current is along the (100) or (110) direction.