Optimum compositions for the low-temperature fabrication of highly ordered FePt [001] and FePt [110] films

The composition dependence of the degree of chemical order S and uniaxial magnetic anisotropy energy K/sub u/ has been investigated for FePt [001] and FePt [110] films deposited at the substrate temperature T/sub s/=300/spl deg/C, and the optimum compositional region for L1/sub 0/ ordering in FePt [110] films has been compared with that in FePt [001] films. It has been found that high S and large K/sub u/ are obtained around the stoichiometric composition for FePt [110] films, whereas they are obtained around an off-stoichiometric Pt-rich composition for FePt [001] films, indicating that the difference in optimum compositions for achieving highly ordered structure between FePt [001] and FePt [110] films at reduced temperature.