Microstructure and magnetic properties of CoPtCr-SiO2 perpendicular recording media

SiO2 added CoPtCr magnetic layer is employed for the perpendicular recording media. The microstructure, magnetic properties, and recording performance of these media are discussed. Very fine grains of the size of similar to7 rim, surrounded by amorphous-like grain boundaries, are realized together with good c-axis orientation normal to the film plane. It is considered that the addition Of SiO2 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 similar to4 x 10(6) erg/cm(3), and high coercivity H-c of similar to4 kOe. Moreover, the medium shows excellent SNR performance together with high thermal stability, indicating a great potential for high-density perpendicular recording media.