Low Temperature Properties of Inhomogeneous Magnetic Multilayers

System of two magnetic layers with nonuniform distribution of anisotropy parameter and exchange coupled by nonmagnetic spacer is studied by means of the Green function approach. Our attention is focussed on the elementary excitations and low temperature magnetisation behavior. The spin wave parameter B in the Bloch law $T^{3/2}$ is found as an oscillatory function of a spacer thickness. The effects of damping leading to non-zero line-width of ferromagnetic resonance peaks are also taken into account. As a result the dependence of resonance line-width on parameters characterizing system under consideration is obtained for the case of uniform anisotropy parameter and for quadratic distribution of this parameter in magnetic layers, respectively.