A ferromagnetic resonance study of NiFe alloy thin films

NiFe alloy films with thicknesses in the range from 60 to 150 Å were sputtered onto Si (0 0 1) wafers by DC magnetron sputtering, and then characterized by in-plane ferromagnetic resonance technique (FMR) at x-band. The FMR field ( H R) and linewidth (Δ H) were studied as a function of the in-plane angle, ϕ H, film thickness, t, and temperature, T. The main effects of temperature on the magnetic properties of these films is to increase the in-plane uniaxial anisotropy and to induce a surface anisotropy that pushes the magnetization out-of-plane. These anisotropies were found to vary with thickness and temperature. The main processes that determine the line broadening are the intrinsic conduction mechanism and the in-plane uniaxial dispersions.