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

Fe-3.4 at% Si/Si
3
N
4
multilayer films were prepared by rf sputtering. Soft magnetic properties were obtained when intermediate layers (SiN
x
) were deposited in an Ar+N
2
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/SiO
2
multilayer films show a high coercivity of more than 5 Oe after annealing under identical conditions. It was confirmed that Si
3
N
4
layers prevent grain growth in magnetic layers more effectively than do SiO
2
layers at high temperatures. It was also confirmed that multilayer structures of Fe-3.4 at% Si/Si
3
N
4
are more thermally stable than are those of Fe-3.4 at% Si/SiO
2
.