MAGNETORESISTANCE PROPERTIES OF THIN-FILMS OF THE METALLIC OXIDE FERROMAGNET SRRUO3

The magnetoresistance of epitaxial thin films (250 to 1000 Angstrom th ick) of the metallic oxide ferromagnet SrRuO3 has been measured at tem peratures ranging from well below to just above the Curie point (appro ximate to 160 K). Measurements using both transverse (nonzero Lorentz force) and longitudinal (zero Lorentz force) geometries cleanly distin guish 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 sho ws strongly hysteretic behavior with high coercive and saturation fiel ds. Through the Curie point, the magnetoresistance magnitude shows a m aximum, which results from the suppression of the phase transition in magnetic field. The temperature derivative of the zero-field resistivi ty also shows a discontinuous jump, as predicted by standard theory.