Preparation of Co-Cr alloy/Ni-Zn ferrite doublelayered films for perpendicular magnetic tape

Co-Cr alloy / Ni-Zn ferrite doublelayered films for perpendicular magnetic recording tape are proposed to improve high frequency characteristics, and their preparation is described. The films were deposited by the ''Ferrite Plating'' method which enables to synthesize the soft magnetic spinel ferrite layers at low temperatures below 100 degrees C and by the facing targets sputtering (FTS) for the Co-Cr layers. It was found that the Co-Cr layers need to compensate the tensile internal stress of 1.0-1.5x10(9)dyn/cm(2) in the ferrite plated backlayers to avoid curling of the tape and to improve adhesion of the backlayers to substrates, and Ar pressure of 0.2-0.3mTorr in the FTS was proper for depositing the Co-Cr layers with the optimum compressive stress and the excellent crystallinity.