  Peculiarities of ferromagnetic resonance response of conducting magnetic
bi-layer films of nanometric thicknesses excited by microstrip microwave
transducers have been studied theoretically. Strong asymmetry of the response
has been found. Depending on the order of layers with respect to the transducer
either the first higher-order standing spin wave mode, or the fundamental mode
shows the largest response.
  Film conductivity and lowered symmetry of microwave fields of such
transducers are responsible for this behavior. Amplitude of which mode is
larger also depends on the driving frequency. This effect is explained as
shielding of the asymmetric transducer field by eddy currents in the films.
This shielding remains very efficient for films with thicknesses well below the
microwave skin depth. This effect may be useful for studying buried magnetic
interfaces and should be accounted for in future development of broadband
inductive ferromagnetic resonance methods.
