Dispersed-oxide seedlayer induced isotropic media

A special Cr target with dispersed-oxide matrix was sputtered as the seedlayer to manufacture an isotropic media with high coercivity and squareness. The dispersed-oxide seedlayer was sputtered on a NiP/Al substrate, then the multilayer films of Cr/CoCrPtTa/C were deposited sequentially by an in-line DC/RF magnetron sputtering system. The orientation ratio (OR) was found to be about one. The media noise and non-linear transition shift (NLTS) of such isotropic media were found much better than those of the oriented media at high recording densities. Magnetic force microscope images (MPM) also showed a clear and sharp bit transition pattern of the isotropic media with dispersed-oxide seedlayer. The film microstructure and crystalline orientation difference between the disks with and without dispersed-oxide seedlayer were examined by using the X-ray diffraction (XRD) and Grazing-incidence X-ray diffraction (GIXRD) techniques.