Structure and magnetic properties of SmCo5/X (X=Fe, Fe-Co, Co) magnetic bilayer films on MgO(110) substrate

Sm17Co83 (at%) films are prepared on bcc-Cr(211), bcc-Fe(211), bcc-Fe65Co35(211), and hcp-Co(11(_)00) underlayers hetero-epitaxially grown on MgO(110) substrates at 500 °C by using a UHV-MBE system. The growth behavior and the structures are investigated by in-situ reflection high-energy electron diffraction and X-ray diffraction. Sm-Co(11(_)00) single-crystal films of RT5 ordered structure with the c-axis lying in the film plane grow epitaxially on the underlayers. Small volumes of amorphous phases are interpreted to be involved in the films deposited on these underlayers. The crystal lattice of RT5 magnetic film is slightly deformed from the bulk hexagonal structure, which is caused possibly by the lattice mismatch with the underlayer. The order degree of film deposited on Cr underlayer is higher (S=0.77) than those prepared on Fe, Fe65Co35, and Co underlayers (S: 0.67-0.71). The films show in-plane uniaxial magnetic anisotropies reflecting the magnetocrystalline anisotropy of SmCo5 crystal.