Abstract
FePt (001) films with a variety of compositions were prepared on MgO (001) substrates by sputtering at reduced substrate temperature Ts of 300°C, and their magnetic properties, particularly the temperature dependence of magnetization were investigated. The film with a Pt-rich off-stoichiometric composition (Fe38Pt62) showed high chemical order and large perpendicular magnetic anisotropy, in contrast to the film with the stoichiometric composition showing poor chemical order. Besides the Curie temperature Tc for Fe38Pt62 showed no large change from that of the bulk ordered alloy with the same composition, however, was lower than that of the fully ordered bulk alloy with the stoichiometric composition. This implies that the films with Pt-rich offstoichiometric compositions have an advantage to thermally assisted magnetic recording which requires moderately low Tc.
