Brillouin scattering from magnons in ferromagnetic thin films of polycrystalline iron

Abstract

In the Brillouin-scattering spectra from thin films of polycrystalline iron, one observes peaks which result from scattering from bulk and surface magnons. Unusual features are present in the spectra. For some scattering geometries, there is a large asymmetry in the intensity between a peak on the Stokes side and the corresponding peak on the anti-Stokes side. We have studied the intensities and positions of these peaks as a function of the light-scattering geometry both theoretically and experimentally and have found very good agreement. The theory gives a good account of the peculiar intensity features of scattering from the standing spin-wave modes, as well as the frequency of the bulk and surface magnons as a function of the angle between the propagation direction and the magnetic field.