Layer-sensitive magnetization, magnetoresistance and ferromagnetic resonance (FMR) study of NiFe/Ag/CoNi trilayer film

We present the layer-sensitive magnetization, magnetoresistance and ferromagnetic resonance (FMR) measurements for the polycrystalline FeNi/Ag/CoNi asymmetric trilayer films at room temperature. The samples were prepared by the UHV magnetron sputtering on silicon. In-plane magnetization measurements showed double-step hysteresis loops. Magnetoresistance (MR) measurements revealed giant magnetoresistance (GMR) effect with magnitudes in 0.15–0.43% range at room temperature. The saturation magnetizations and the interaction between layers were studied by ferromagnetic resonance and revealed an undistinguishably weak interlayer coupling from out-of-plane geometry of measurements. The MR data are interpreted based on incomplete domain alignment model for polycrystalline magnetic films.