Sputter-deposited (Fe-Pt)-MgO composite films for perpendicular recording media

Aiming for improvement of a pure Fe–Pt perpendicular double-layered medium, a composite film of (Fe–Pt)–MgO with ordered FePt-fct(001) phase was prepared by sputtering on heated substrates without any post-annealing. It was found that the (Fe–Pt)–MgO films exhibited a large perpendicular magnetic anisotropy in the preparation condition of lower substrate temperature than that were required for the films with other additives such as Al₂O₃ and SiO₂. The (Fe–Pt)–MgO composite films showed hysteresis loop with relatively steep slope at and smaller magnetic domains than that of the pure Fe–Pt film. A higher recording resolution was achieved for the perpendicular double-layered medium with the (Fe–Pt)–MgO composite film.