Co/Pt multilayers perpendicular magnetic recording media with thin Pt layers and high perpendicular anisotropy

Summary form only given. It has been found that Co/Pt multilayers films have high perpendicular magnetic anisotropy when Co layer thickness is thicker than Pt layer one. The authors show that Hc increases with decreasing Pt layer thickness and has a maximum, 1.9 kOe at 0.13 nm for the samples of Pt underlayer/[Co(0.44 nm)/Pt(0/spl sim/1.2 nm)]/sub 20/ deposited by sputtering at 4 Pa Ar gas pressure. K/sub /spl perp// has also increased with decreasing Pt layer thickness, 3/spl times/10/sup 6/ to 10/spl times/10/sup 6/ erg/cm/sup 3/. They also show that Hc is large between 0.3 and 0.5 nm in Co layer thickness at 0.13 nm Pt layer thickness. Hc has increased with Co/Pt multilayers deposition Ar gas pressure and /spl alpha/(dM/dH at Hc) has 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, Ms:800 emu/cm/sup 3/, /spl alpha/:4, K/sub /spl perp//: 10/spl times/10/sup 6/ erg/cm/sup 3/ have been obtained. And inserting FeTaC soft magnetic layer between glass substrate and Pt underlayer, those of Hc:5.8 kOe, S:0.87, /spl alpha/:1.8 have also been obtained. Grain size of Co/Pt multilayers has been 10 nm in diameter. Those characteristics imply that Co/Pt multilayers with thin Pt layer are very promising as perpendicular magnetic recording media of high recording density because of high K/sub /spl perp//, low noise and thin recording layer (less than 10 nm).