CoCrTa/Cocrptta bi-layer magnetic thin films

摘要

Double layer, or bi-layer, magnetic films are deposited over a substrate with an underlayer. The bi-layer film is a film of two different magnetic layers which have different chemical composition, deposited with no spacer layer between the two layers. The lower magnetic layer should be of a low noise magnetic material, while the upper magnetic layer should be a high coercivity magnetic material. The bi- layer film exhibits a single response to magnetic recording and a joint coercivity different from the coercivity of either layer by itself. A preferred double layer media uses a CoCrTa layer deposited under a CoCrTaPt layer, with the CoCrTa layer comprising 30 to 70% of the total film thickness. The double layer film produces magnetic media with higher coercivity and lower media noise as compared to single layered films of either of the materials of the magnetic layers.