Surface topology and magnetic properties of FePt alloyed thin films

Dependency of Ar pressure on the surface topology and magnetic properties of as-deposited and air-annealed 120 nm thick FePt thin films were investigated. The higher the Ar pressure was, the rougher the surface of as-deposited films became. After annealing in the air, the surface became much rougher which was due to formation of Fe oxide on the surface. The oxidation was much accelerated in the films with rougher surface. This accelerated oxidation resulted in a high order-disorder transformation rate and higher coercivity.