Co-Pt multilayers perpendicular magnetic recording media with thin Pt layer and high perpendicular anisotropy

It was found that Co-Pt mutilayers films had high perpendicular magnetic anisotropy when Co layer thickness was thicker than Pt layer one. He increased with decreasing Pt layer thickness and had a maximum at 0.13 nm for the samples of Pt underIayer/[Co(0.44 nm) /Pt(0 similar to 1.2 nm)](20) deposited by sputtering at 4 Pa Ar gas pressure. K [ had also increased with decreasing Pt layer thickness, 3 x 10(6) to 10 x 10(6) erg/cm(3). He increased with Co-Pt multilayers deposition Ar gas pressure. And alpha(dM/H-at (Hc)) decreased with Pt underlayer deposition Ar gas pressure. Increasing deposition pressures of Co-Pt multilayers and Pt underlayer to 7.5 Pa, the characteristics of Hc : 4.7 kOe, S : 0.96, alpha : 4, K-perpendicular to : 10 X 10(6) erg/cm(3) were obtained. And inserting FeTaC soft magnetic layer between glass substrate and Pt underlayer, those of Hc : 5.8 kOe, S : 0.87, alpha : 1.8 were also obtained. Those characteristics implied that Co-Pt mutilayers with thin Pt layer had the possibility of perpendicular magnetic recording media for high recording density because of high K-L and thin recording layer (less than 10 nm).