Influence of layer defects on the dynamical properties of ferromagnetic semiconducting thin films

A Green's function technique is applied for the s-d model to study the spin wave spectrum including damping effects. It is shown that defect layers in ferromagnetic thin films, layers with impurities or vacancies, with dislocations, can induce strong increasing or decreasing of the magnetization, the phase transition temperature, the spin-wave energy, and the damping due to different exchange interactions in the defect layers. The results could explain the obtained experimental data for various thin films.