Dissipation of the spin wave energy in magnetic multilayer films

It is shown that the penetration of standing spin waves into a layer with high damping is one of the channels of energy dissipation of these waves. The line broadening of spin wave modes due to this layer increases with the mode index and may be much larger than the natural linewidth associated with a layer having low damping. The linewidths of spin wave modes are found to be anisotropic, which is due to the dependence of the penetration depth of spin waves into the high-damping layer on the orientation of the external magnetic field with respect to the film. A theoretical model is proposed, which is consistent with the experimental data.