Microstructure and magnetic properties of oxidized Fe-Pt films with high rate order-disorder transformation

Structural and magnetic properties of air-annealed Fe1-xPtx films with a hi gh rate order-disorder transformation were analyzed by transmission electro n microscopy, Auger electron microscopy, Rutherford backscattering spectros copy and vibrating sample magnetometer. The air-annealed films consisted of three layers, that is, crystalline Fe oxide layer, Fe-Pt upper layer with small grains, and Fe-Pt bottom layer with large grains from the film surfac e. Those layers were nonmagnetic, magnetically hard, and with magnetically hard and soft phase, respectively. The Fe content in Fe-Pt metallic layer d ecreased and then increased with increasing film depth from the oxide/metal interface.