Abstract
Linear response theory and the semiclassical torque equation are employed to evaluate the response functions (or Green functions) for thin films of Heisenberg ferromagnets. The results provide a description of the standing bulk spin waves in the film and the localised surface spin waves. The effects due to surface anisotropy (or 'pinning') and modified surface exchange parameters are discussed. The Green functions are used to analyse the dispersion properties and the power spectra of the various spin wave excitations, and numerical examples are presented.