HIGH SIGNAL-TO-NOISE RATIO OF A CR-RICH COCRPT PERPENDICULAR MEDIUM WITH A LARGE MEDIUM THICKNESS

A Cr-rich (Co72Cr28)(94)Pt-6 perpendicular medium with a large thickne ss of 300 nm, integrated with an MR head designed for longitudinal rec ording, achieved a high signal-to-noise ratio of 37 dB at 100 kFCI and a D-50 of 150 kFCI. A high Pt content of 17-22 at.% is effective for increasing the Kk value and signal amplitude at 10 kFCI, and for decre asing the write demagnetization. However, it also decreases the S/N at 100 kFCI and the D-50. The signal amplitude rapidly increases with th e Pt content from 0 to 6 at.%, and saturates at around 6 at.%. This co ntributes to the high SIN obtained at a Pt content of 6-11 at.%. Compa red with a longitudinal medium optimized for the same MR head, the pro posed medium has a 2 dB higher S/N at 100 kFCI, a 1.3 times larger D-5 0, and a 1.5 times larger signal amplitude at 10 kFCI. The thickness o f the medium will contribute to the thermal stability of magnetic bits at future high recording density of 10 Gbits/in(2) and beyond.