Spin-wave resonance of exchange-coupled three-layers FeNi/Cu/FeNi planar structures

Abstract

The spectrums of standing exchange spin waves into magnetic sandwich Ni80Fe20/Cu(tCu)/Ni80Fe20 were studied by spin-wave resonance method. The layer of diamagnetic Cu depending on its thickness tCu provided both positive and negative exchange interaction between ferromagnetic layers. It was shown that spin waves modes of SWR spectra which are described by well-known relation Hacres(n)~ n2 are standing acoustic exchange spin oscillations of individual ferromagnetic layers, regardless of a sign of interlayer exchange couple. It was detected that spin modes which are optical satellites of acoustic SWR peaks are described by the dependence of the resonance field Hopres(n)~ n5/2 or Hopres(n)~ n2 depending on the boundary conditions established on inner interfaces. Keywords: spin-wave resonance, surface anisotropy constant, exchange interaction constant, interlayer exchange interaction.