Magnetic Properties of Fe-Co-Ti Thin Films

Sputtered (Fe_100-yCo_Y)_100-XTi_X (0≤X≤5, 23≤Y≤53) films were studied with emphasis on the dependence of the soft magnetic properties on composition, annealing temperature and film thickness. After annealing at 823K for 3600 s, the permeability of the film system had a maximum of 1650 at (Fe₆₉Co₃₁)₉₇Ti₃. The corresponding saturation magnetic flux density was 2.2 T. When the lattice constant of Fe-Co film expands by about 0.2%, the permeability reaches a maximum; when the film thickness reaches 1357 nm, the permeability decreases to 500. The permeability of an (Fe₆₉Co₃₁)₉₇Ti₃/ZnO multi-layer film annealed at 773K for 3600 s is 1100; this is about twice the permeability of a single-layer film.