RF-bias effect on structural and magnetic properties in CoCrPt/Cr/sub 75/Ti/sub 25//CoTi trilayer type longitudinal recording media

Abstract

The effects of an rf substrate bias on the structural and magnetic properties of the CoCrPt/Cr/sub 75/Ti/sub 25//CoTi trilayer type longitudinal recording media deposited on glass substrate have been studied. It was found that the coercivity of 30 nm thick CoCrPt films deposited on Cr/sub 75/Ti/sub 25//CoTi underlayer was 4000 Oe by substrate bias of 100 W rf, which is 800 Oe increase than the non-biased case. X-ray diffraction indicated that the rf-bias to substrate improved the Co (101~0) and (112~0) plane textures of the CoCrPt magnetic layer. From RES analyses, Pt content of the CoCrPt magnetic layer increased with rf-bias power. In addition to the Pt increase, better lattice matching between the CoCrPt magnetic layer and the Cr/sub 75/Ti/sub 25//CoTi underlayer was obtained through the expansion of the lattice parameter, a and c of Co in the CoCrPt with the substrate bias. These two factors are thought to be the origin of the coercivity increase.