Effect of Ni doping on the microstructure and magnetic properties of FePt films

FePtNi films with different Ni contents were deposited on glass substrates by RF magnetron sputtering, and the L10-FePtNi films were obtained after the as-deposited samples were subjected to vacuum annealing. The magnetic properties, structures, and orientations of the L10-FePt films with Ni doping were studied. The results show that with increasing Ni content, the (001) peak position of the FePtNi films shifts to a higher angle in comparison with FePt, which suggests that there is partial Ni substitution in the L10 lattice. The perpendicular coercivity decreases from 661 to 142 kA/m and magnetization decreases from 512 to 433 kA/m with increasing Ni content. In comparison with FePt films, the FePtNi films can effectively reduce the Curie temperature, which makes FePtNi films promising media candidates in thermally assisted recording (TAR).