The structural transition from epitaxial Fe/Pt multilayers to an ordered FePt film using low energy ion beam sputtering deposition with no buffer layer

摘要

An epitaxial L1_0 FePt thin film grown from an [Fe(10 A)/Pt(10 A)]_(15) multilayer with the orientation of (001) was prepared by an ion beam sputtering deposition method without buffer layer. From the measurement data of X-ray diffraction and X-ray reflectivity, the multilayer structure was totally disappeared and a uniform FePt alloy thin film was formed at temperatures higher than 600 ℃. For the as-deposited thin film grown at 100 ℃, the multilayer already possesses an epitaxial structure. The epitaxial relation is FePt(001)[100]// MgO(001 )[100] and this epitaxial relation persists after sequential high temperature annealing. An epitaxial L1_0 ordered FePt(001) film with order parameter of 0.95 was obtained when the annealing temperature reached 650 ℃. The ordered FePt(001) thin film has a perpendicular magnetic anisotropy with a squareness of 0.95 ± 0.03 on the magnetic hysteresis loop. This experiment demonstrates that the low energy ion beam sputtering deposition will preserve the epitaxial relation with no buffer layer between multilayer and substrate.