Magnetic Structure and Noise Characteristics of Co-Cr Films Prepared by Sputter-deposition with Low Discharge Voltage

Abstract

The Co-Cr disk media for perpendicular recording were prepared by sputter-deposition at high Ar pressures which enables low voltage discharges. The magnetic structure and the noise characteristic of the disk media were investigated. It was found that the Co-Cr medium deposited at a high Ar pressure showes a high perpendicular anisotropy field of about 5 kOe as well as a high perpendicular coercivity even if the medium is deposited at room temperature. The high anisotropy field is supposed to be originated from the crystalline anisotropy by the temperature dependence of the coercivity. The angular dependence of the coercivity and the low noise characteristic, which are almost the same as those of a medium prepared at a low Ar pressure and a high substrate temperature, suggest that the magnetization reverses mainly by a rotation mechanism and the magnetic particles are well separated. It was concluded that the media prepared at high Ar pressures have a fine and isolated magnetic structure, which might be one of the suitable structure for high density recording.