CoPt–C nanogranular magnetic thin films

Cobalt–platinum–carbon thin film was deposited with a chemical composition of ${\mathrm{Co}}_{\mathrm{50}}{\mathrm{Pt}}_{\mathrm{15}}{\mathrm{C}}_{\mathrm{35}}.$ The film had a nanogranular morphology with a grain size ranging from 5 to 15 nm. It consisted of cobalt–platinum grains which had a faulted hexagonal close-packed phase and were separated by graphitelike carbon boundaries. The film in-plane coercivity was 1500 Oe, compared to a few hundreds oersteds in the case of cobalt–carbon. This result establishes a way of fabricating high coercivity cobalt–carbon based materials, which have potential applications as high density magnetic recording media.