Effect of Cu Substitution on the Magnetic Properties of SmCo5 Film with Perpendicular Magnetic Anisotropy

SmCo5 film with perpendicular magnetic anisotropy is a promising candidate ultrahigh-density magnetic recording medium due to its huge magnetocrystalline anisotropy. This paper investigates the effect of Cu substitution for Co on the magnetic properties and microstructure of SmCo5 film by simulations and experiments. The simulation results based on first-principles theory show that Cu substitution for Co in SmCo5 can reduce the total exchange- correlation constant and increase the coercivity of SmCo5 film. Sm(Co,Cu)(5)/Cu/TiW film samples with different Cu doping were fabricated on quartz glass substrates by radiofrequency (RF) magnetron sputtering, and the dependence of the coercivity of the Sm(Co,Cu)(5) film on the Cu doping and annealing conditions was studied. The experimental results demonstrate that Cu doping can decrease the grain size and increase the coercivity of SmCo5 film. By optimizing the sputtering and annealing conditions, perpendicular coercivity of 3796 Oe was obtained in Sm(Co0.72Cu0.28)(5) film.