Paramagnetic anisotropic magnetoresistance in thin films of SrRuO3

SrRuO3 is an itinerant ferromagnet and in its thin film form when grown on miscut SrTiO3 has Tc of ∼150 K and strong uniaxial anisotropy. We measured both the Hall effect and the magnetoresistance (MR) of the films as a function of the angle between the field applied and the normal to the films above Tc. We extracted the extraordinary Hall effect that is proportional to the perpendicular component of the magnetization and thus the MR for each angle of field applied could be correlated with the magnitude and orientation of the magnetization induced. We fit the MR data with a second order magnetization expansion, and it indicated large anisotropic MR in the paramagnetic state. The extremum values of resistivity were not obtained for currents parallel or perpendicular to the magnetization, probably due to crystal symmetry.