MAGNETIC-PROPERTIES AND READ WRITE CHARACTERISTICS OF CO-CR-(PT, TA) (CR-TI,CR) THIN-FILM MEDIA/

A Cr-Ti underlayer is found to enhance the in-plane coercive forces of Co-Cr-Pt and Co-Cr-Ta films; the maximum coercive force was 3.5 kOe f or (CoCr0.15)0.84Pt0.16/CrTi0.2. The crystallites of Cr-Ti grow in a m ore highly oriented and uniform manner than ones of Cr, and their latt ice spacings are closer to those of Co alloys than Cr, improving the e pitaxial growth of Co-alloy crystallites with c-axis in-plane oriented components on the Cr-Ti underlayer. The crystalline anisotropy consta nt of Co-Cr-Pt with a high Pt concentration is found by torque measure ment to be larger than that of Co-Cr-Ta. These can produce extremely h igh coercive forces in Co-Cr-Pt/Cr-Ti. The C/Co-Cr-Pt/Cr-Ti thin film media with high coercive forces show excellent read/write characterist ics; the linear densities at 50% signal drop are very high, 175 and 10 1 kFCI, for the C/Co-Cr-Pt/Cr-Ti media at head-to-magnetic layer spaci ngs of 0.01 and 0.07 mum.