Ferromagnetic resonance in metallic multilayers, I. Formal treatment

We present here a method for calculating the power absorbed in the ferromagnetic resonance of a sample consisting of metallic multilayers, with arbitrary directions of the applied static field. It is presented in as general a form as possible and then a number of simplifications are introduced to make the numerical calculation reasonable. These simplifications are shown to be justified and applicable for a large class of problems. In a following paper, the method is applied to a particular problem, and a semiquantitative model of the resonance behavior is presented.