Soft Magnetic Properties of Multilayered Fe-2~4 at% Si Films

Fe-3.4 at% Si/Si3N4 multilayer films were prepared by rf sputtering. Soft magnetic properties were obtained when intermediate layers (SiNx) were deposited in an Ar+N2 atmosphere and had a composition ratio (N/Si) of about 4/3. Interestingly, these films retain a low coercivity of about 2 Oe after annealing (at 600°C for 2 hrs), while Fe-3.4 at% Si/SiO2 multilayer films show a high coercivity of more than 5 Oe after annealing under identical conditions. It was confirmed that Si3N4 layers prevent grain growth in magnetic layers more effectively than do SiO2 layers at high temperatures. It was also confirmed that multilayer structures of Fe-3.4 at% Si/Si3N4 are more thermally stable than are those of Fe-3.4 at% Si/SiO2.