Thermal Stability of Compositionally Modulated Amorphous Nitride Alloy Films

Co-based amorphous alloy films composed of non-nitride and nitride layers were prepared by N2 reactive sputtering. The layered films showed soft magnetic properties when the layer thickness was less than 300 Ã…. The saturation magnetization (4¿Ms) was increased by nitriding. The 4¿Ms of the non-nitride films in the present study was about 7400 G, and that of the layered films was about 8400 G. The layered structure changes into a compositionally modulated structure after annealing above 400°C, and the 4¿Ms of films is thereby increased up to 11,300 G. The resulting compositionally modulated films are thermally stable and were found to have a high crystallization temperature (Tx ≫ 600°C).