Abstract
The relation between the magnetic anisotropy field of grains and media noise in vacuum-evaporated Co-O films with oblique anisotropy is studied. The ratio of the coercive force to the magnetic anisotropy field of grains, which indicates the degree of magnetic isolation of the grains. With increasing thickness of the films, the ratio decreases and the media noise increases. The increase of the noise is caused by both the enlarged volume of the films and the weakened magnetic isolation of the grains. Though the degree of the magnetic isolation increases with increasing oxygen content, the media noise increases. It is considered that the increase of the noise is caused by the deterioration of the crystallographic orientation. The degree of magnetic isolation of the grains depends on the grain length. By making the films multilayered, the grain length is kept short and the degree of magnetic isolation of the grains is high.
