Abstract
The magnetic domain structures of Co-Cr films for per- pendicular recording media sputter-deposited at high Ar pressures (70 Pa) were investigated and compared with those of films deposited at low Ar pressures (0.2 Pa). The relationship between the magnetic domain structures and the medium noise was also studied. Co-Cr films deposited at high Ar pressures and at room temperature have a cluster-like magnetic domain structure, while those deposited at low Ar pressures and at room temperature have a maze-like magnetic domain structure. The magnetic domain size is much larger than the grain size in low- temperature-deposited films, whereas the sizes are comparable in high-temperature-deposited films. With increasing deposition temperature, the domain size becomes smaller, approaching the grain size. It was found that low medium noise corresponds not to smaller domain size, but to the strength of the longer wavelength component of the mag- netic domain in the dc remanent state.
