  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.
