SOFT MAGNETIC-PROPERTIES OF FE-N AND FE-SI-N THIN-FILMS SPUTTERED IN (AR+N2) PLASMA

Soft Magnetic properties for sputtered (O~3wt%)Si-Fe alloy thin films fabricated in (Ar+N2) plasma were investigated in connection with metallurgical structure. 2.7wt%Si-Fe film annealed at 400°C shows high effective permeability μeff about 1600 at 5MHz. It has been observed that this film consists of a-phase with grain size less than 150A and a slight expansion of lattice spacing of the (110) plane. To understand the magnetoelastic effect on permeability, the total magnetic anisotropy in the (110) plane of each grain,U(110)‘ were calculated for shear and tetragonal deformation modes. U(110) increases with increasing the strain for shear deformation mode, while U (110) decreases as the positive strain increases and has a minimum for tetragonal deformation mode. It is supposed that the decrease in total magnetic anisotropy in each grain through the magnetostrictive anisotropy due to tetragonal deformation and the reduction of grain size are essential to realize high μeff for Fe-Si films. © 1990 IEEE