Nanocomposite CoPt:C films for extremely high-density recording

Abstract

Nanocomposite CoPt:C films were investigated as potential media for extremely high-density recording. An annealing temperature of over 600 °C is necessary to form nanocomposite CoPt:C films consisting of C matrix and fct CoPt nanocrystallites with grain sizes of 8–20 nm and coercivities of 3–12 kOe. Coercivity and grain size increase with increasing annealing temperature and decreasing C concentration and they are insensitive to film thickness. The average activation volumes are about 0.9×10−18 cm3. The properties of these nanocomposite CoPt:C films can be tailored to satisfy the thermal stability, coercivity, and media noise requirements for extremely high-density recording.