Abstract
SiO_2 added CoPtCr magnetic layer is employed for perpendicular recording media. The microstructure, magnetic properties, and recording performance of these media are discussed. Fine grains with the size of 〜7 nm, surrounded by amorphous-like grain boundaries, are realized. It is considered that the addition of SiO_2 to CoPtCr is very effective to realize well isolated fine grain structure without disturbing the epitaxial growth of CoPtCr grains on Ru underlayer. The medium with 12 nm-thick recording layer shows a large perpendicular anisotropy K_u of 〜4x1O^6 erg/cm^3, high coercivity H_c of 〜6 kOe, and excellent SNR performance. These results indicate that the CoPtCr- SiO_2 granular medium has a great potential for high-density perpendicular recording media.
