摘要
A strong correlation has been noted between the structural order parameter of an epitaxial L1 0 Fe/Pt thin film and the corresponding perpendicular magnetic anisotropy (PMA) and orbital magnetic moment. This relationship is studied in detail here. An epitaxial L1 0 FePt thin film grown from an [Fe(10 Å)/Pt(10 Å)] 15 multilayer with (001) orientation was prepared using ion beam sputtering deposition. The Fe/Pt multilayer was transformed into L1 0 alloy at an annealing temperature of about 500 °C. When annealed at 700 °C, the out-of-plane order parameter of L1 0 FePt reached 0.95, with the squareness close to 1 and the magnetocrystalline anisotropy constant reaching 3 × 10 7 erg/cm 3 . This indicates that the ordered FePt film has a strong PMA effect. The plane-normal orbital-to-spin magnetic moment ratios are 0.088, 0.149 and 0.174 for the samples of Fe/Pt multilayer without annealing, after annealing at 500 °C and the ordered FePt film after 700 °C annealing, respectively. The results suggest that the higher order parameter results in a stronger hybridization and spin-orbital coupling between Fe and Pt atoms. Also, the higher orbital magnetic moment anisotropy implies that the plane-normal orbital-to-spin magnetic moment ratio increases.