Co-Pt-Ti[O.sub.2] composite film for perpendicular magnetic recording medium

A new type of oxide composite film was proposed as perpendicular magnetic recording medium. The storage layer is composed of Co-Pt and Ti-oxide. By transmission electron microscopy (TEM) observation, the film exhibited a well isolated fine granular structure with small and uniform Co-Pt grains surrounded by Ti[O.sub.2]. More sufficient segregation by Ti[O.sub.2] was realized from the beginning of the layer growth compared with other oxide addition film, resulting in a magnetically weak coupled structure. This film has a relatively large magnetic anisotropy constant ([K.sub.u]) and saturation nmgnetization ([M.sub.s]) of more than 5 x [10.sup.6] erg/[cm.sup.3] and about 800 emu/[cm.sup.3], respectively. The structure was brought about by a high sputtering gas pressure of Co-Pt-Ti[O.sub.2] film deposition. Index Terms--Film microstructure, perpendicular anisotropy, perpendicular magnetic recording medium, sputtered thin film.