Low-temperature fabrication of L10 ordered FePt alloy by alternate monatomic layer deposition

L10 ordered FePt alloy films with large magnetic anisotropy have been successfully prepared by alternating Fe(001) and Pt(001) monatomic layers on MgO (001) substrates at low temperatures below 230 °C. In addition to the fundamental (002) peak, (001) and (003) superlattice peaks have clearly been observed in the x-ray diffraction patterns for all the samples, indicating the formation of L10 ordered structure. The magnetization measurements show that all the samples are perpendicularly magnetized. Large uniaxial magnetic anisotropy (Ku=3.0×107 erg/cc) and high chemical ordering (long-range order parameter S=0.7±0.1) have been obtained even at the substrate temperature Ts=200 °C. The magnetization curves show good magnetic squareness (Mr/Ms∼0.9) for the samples grown at Ts⩾160 °C.