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

Abstract

L 1 0 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.