Low-temperature fabrication of high-coercivity L1₀ ordered FePt magnetic thin films by sputtering

We report that fully ordered L1₀ FePt magnetic thin films with high coercivity can be fabricated by a simple sputtering method at a substrate temperature of 300°C. Although fcc → L1₀ ordering proceeds only above 600°C in ex situ annealing of disordered FePt films, the ordering occurs spontaneously by surface diffusion during the sputtering process of FePt alloy upon heating the substrate at 300°C. High coercivity larger than 7 kOe was achieved from the as-sputtered state.