Spin wave parameter in the system of non-equivalent exchange coupled layers

The system of two ferromagnetic layers characterized by different exchange parameters and indirectly coupled by nonmagnetic spacer has been considered in low temperature region. The spin wave parameter B describing the Bloch's T ^3/2 law has been calculated as a function of thickness and exchange parameters of constituent layers employing the Green fuction method. It has been shown that anisotropy in the interface region influences the dependence of B on the inverse thickness of the system.