Magnetoresistance properties of thin films of the metallic oxide ferromagnetSrRuO3

The magnetoresistance of epitaxial thin films (250 to 1000 Å thick) of the metallic oxide ferromagnet ${\mathrm{SrRuO}}_3$ has been measured at temperatures ranging from well below to just above the Curie point (≊160 K). Measurements using both transverse (nonzero Lorentz force) and longitudinal (zero Lorentz force) geometries cleanly distinguish between an orbital contribution, present only at low temperature, and a spin-flip scattering contribution, present at all temperatures, to the resistivity in magnetic field. The magnetoresistance also shows strongly hysteretic behavior with high coercive and saturation fields. Through the Curie point, the magnetoresistance magnitude shows a maximum, which results from the suppression of the phase transition in magnetic field. The temperature derivative of the zero-field resistivity also shows a discontinuous jump, as predicted by standard theory.