X-Ray and Magnetic Studies of CrO2 Single Crystals

The oxygen parameter of CrO2, which has the rutile structure, has been determined to be u=0.301±0.004. Single-crystal measurements of cell constants over the temperature range −200° to +200°C show the unusual decrease in the c axis with increasing temperature in agreement with x-ray powder results reported by other workers. An estimate of the magnetocrystalline anisotropy has been obtained from measured magnetization curves of a small single-crystal sphere of CrO2. The directions of easy magnetization lie in (100) planes at an angle of approximately 40° to the tetragonal axis.