Determination of the spin polarization of half-metallic CrO₂ by point contact Andreev reflection

Adreev reflection at a Pb/CrO2 point contact was used to determine the spin polarization of single-crystal CrO2 made by chemical vapor deposition. The spin polarization was found to be 0.96 ± 0.01. A surface barrier layer strongly reduced the apparent spin polarization of CrO2.