Influence of oxygen content on the reduction of the ordering temperature of L1/sub 0/ FePtCu alloy

The influence of the residual oxygen on the ordering (transformation from fcc to fct) temperature of sputtered Fe-Pt-Cu films was investigated. Secondary ion mass spectroscopy analysis revealed that high oxygen content increases the onset temperature of the ordering process. The oxygen is brought into an Fe-Pt-Cu film during the deposition process and forms stable Fe-O compound. This might increase the ordering temperature as well as prevent the coalescence of grains, that is, the nucleation of phase transformation. A hot-pressed Fe-Pt composite target which contains oxygen of 50 ppm was developed. This target is also effective for reducing the ordering temperature of Fe-Pt films.