Microstructure and magnetic properties of self-assembled FePd–SiN films

Abstract

Self-assembled FePd–SiN nanocomposite films were fabricated successfully by direct current (dc) reactive magnetron sputtering and then followed by vacuum annealing. The effects of Si–N matrix and annealing temperature on the structure and magnetic properties were investigated. The as-deposited films show typical magnetically soft behavior with face-centered cubic (fcc) FePd phase, which transforms into the face centered tetragonal (fct) structure after thermal annealing at 600 °C. The grain size of FePd increased with the annealing temperature but decreased with increasing Si–N content. Increasing Si–N content forms SiN-rich amorphous phase distributed between the FePd nanograins, which inhibits the growth of the FePd particles. The fct-FePd films annealed at 700 °C exhibited moderate coercivity, up to 2330 Oe at room temperature. These FePd–SiN films have shown promise for high-density magnetic recording medium.