Magnetization reversal in half-metallic epitaxial CrO2 films

We have investigated the magnetization reversal in thin films of the half-metallic ferromagnet chromium dioxide, CrO2, grown on single crystal TiO2 (100) and (110) substrates. X-ray diffraction analysis indicated epitaxial growth of CrO2 in the rutile crystal structure with the c axis (also the magnetization easy-axis), lying in the plane of the film. Direct, real-time observation of the magnetization reversal revealed that reversal occurs via nucleation of domain walls, and their subsequent motion perpendicular to themselves. The reversed domains are formed when the applied field is close to the coercive field Hc of the CrO2 film, and the reversal is complete within a small field range, indicating a small dispersion in the film switching field.