Effects of C layer on the microstructure and magnetic properties of FePt recording media films

FePt/C mutilayer films were fabricated by magnetron sputtering system, then postannealed in vacuum. X-ray diffraction measurements show that the as-deposited films were disordered and the ordered L10 structure was obtained by annealing the film at 600 °C with the c/a ratio 0.968. Magnetic investigation indicated that [FePt (2.5 nm)/C (2.0 nm)]10 film has the optimal magnetic properties with coercivity of 3245.1 Oe. By annealing the [FePt (2.5 nm)/C (2.0 nm)]10 film at 600 °C, magnetic particles with the size of about 10 nm dispersed uniformly in nonmagnetic C matrix was observed by an atomic force microscopy.