A magnetostatic theory of the response functions for a finite-thickness ferromagnetic slab and the application to Brillouin scattering

Calculations are given for the spin-dependent response functions (or Green functions) of a finite-thickness ferromagnetic slab using magnetostatic theory. The results are employed to obtain expressions for the integrated intensities for Brillouin scattering from the surface (magnetostatic) modes and bulk spin-wave modes of a ferromagnetic slab. Numerical estimates are made to compare the theory with recent experimental measurements for Fe and EuO, and it is found that many of the experimental observations can be satisfactorily explained.