Preparation of L10-FePt film for perpendicular magnetic recording media by using FePt/Au mutilayers

FePt/Au mutilayers were deposited on 100℃ MgO（001） single crystal substrate by magnetron sputtering. The influence of the FePt/Au multilayer structure on the ordering temperature, coercivity （ＨC）, perpendicular magnetic anisotropy （PMA）, FePt grain size and interparticle exchange coupling （IEC） of films were studied. Results show that the film possesses high ＨC, excellent PMA, small grain size and weak interparticle exchange coupling after annealing. The results of HRTEM reveal that Au can relieve mismatch between MgO and FePt lattices, leading to excellent PMA. Moreover, the FePt/Au interface energy, the stress energy due to the mismatch between FePt and Au lattices and the diffusion of Au atoms promote the ordering of FePt film. This leads to the decrease of ordering temperature and considerable increase of ＨC. Au atoms partly diffuse to the boundaries of FePt phase and function as grain finer and particle isolator, which decrease the FePt grain size and IEC.