Determination of the Spin Polarization of Half-Metallic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>CrO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>by Point Contact Andreev Reflection

Abstract

Andreev reflection at a $\mathrm{Pb}/{\mathrm{CrO}}_{2}$ point contact has been used to determine the spin polarization of single-crystal ${\mathrm{CrO}}_{2}$ films made by chemical vapor deposition. The spin polarization is found to be $0.96\ifmmode\pm\else\textpm\fi{}0.01$, which confirms that ${\mathrm{CrO}}_{2}$ is a half-metallic ferromagnet, as theoretically predicted.