Theoretical and experimental approach to spin dynamics in thin magnetic films

The Landau-Lifshitz (L-L) equation describing the time dependence of the magnetisation vector is numerically integrated fully without any simplifying assumptions in the time domain and the magnetisation time series obtained is Fourier transformed (FFT) to yield the permeability spectrum up to 10 GHz. The non linear results are compared to the experimental results obtained on magnetic amorphous thin films of Co-Zr, Co-Zr-Re. We analyse our results with the frequency response obtained directly from the Landau-Lifshitz equation as well as with the second order Gilbert frequency response