Development of Co-alloys for perpendicular magnetic recording media

Exploring new Co-alloy compositions to achieve both chemical segregation and suitable magnetic properties is a priority task for the development of future perpendicular magnetic recording media. With proper interlayer (IL) design, columnar Co-alloy grains with narrow orientation distribution (/spl Delta//spl theta//sub 50/< 6/spl deg/) have been obtained on thin ILs (4 nm thick). We demonstrate CoCrPtB-alloys with full remanence squareness and large negative reverse field (H/sub r/<-1.5 kOe) at low IL and magnetic layer thickness of 4 and 11 nm, respectively. It is also shown that carbon overcoat thickness reduction results in a signal-to-noise ratio gain of about 0.5 dB/nm.