  We have measured the transport spin-polarization of epitaxial thin films of
the conductive ferromagnetic oxide, SrRuO3, using Point Contact Andreev
Reflection Spectroscopy (PCAR). In spite of the fact that spin-up and spin-down
electronic densities of states at the Fermi level for SrRuO3 calculated from
band structure theory are practically the same, the experimental transport spin
polarization for these films was found to be about 50%. This result is a direct
consequence of the Fermi velocity disparity between the majority and minority
bands and is in good agreement with our theoretical estimates.
