Magnetization and FMR studies in Ni-Ag multilayers

We have prepared Ni-Ag multilayers and studied their magnetization (M) (68 - 293 K) and FMR properties (290 K). The Ag layer thickness (t Ag) was kept constant at 5 nm and that of Ni (t Ni) varied from 0.7 to 10 nm. At 4 K, M decreases slightly from the bulk value but remains much higher than that reported so far in other systems. We attribute this to the presence of Ag in the pores of thin layers of Ni and their mixing which leads to an increase in Ni moment. FMR results are shown to indicate to relatively high M for t < 3 nm where no anisotropy expected. The large increase in the line width in these cases also confirms the presence of magnetic inhomogeneities.