Effects of surface oxidization of amorphous Ni-based alloy seed layers on noise in CoCrPt/CrTi media

New amorphous seed layers of NiCrZr and NiTa have been developed to reduce the noise of CoCrPt/CrTi thin film media on a glass substrate. By exposing the surfaces of the Ni-based amorphous seed layers to low pressure oxygen of the order of 10/sup -3/ Pa, the crystal orientation of the CoCrPt magnetic layer is changed from random-like to (11.0), and the magnetic crystal grain size is reduced as in the case of Co-based amorphous seed layer of CoCrZr. These changes in microstructure result in higher coercivities and lower media noises in both cases for the NiCrZr and NiTa seed layers. The grain size distribution of the magnetic layer is also reduced by the surface oxidization of the seed layer. This also contributes to improvements in read/write performance of the media.