Static and dynamical properties of circular NiFe/Cu/Co nanodisks

Abstract

We present an experimental investigation of the static and dynamical properties of array of Ni80 Fe20 (10 nm) Cu (10 nm) Co (10 nm) disks with diameter of 230 nm and edge-to-edge spacing of 160 nm. Magnetization reversal process studied by superconducting quantum interference device magnetometry, resonant scattering of polarized soft x-ray, and three-dimensional micromagnetic simulations reveals that the interlayer magnetostatic interaction and the different coercivities of the two layers are the key factors that determine the magnetization reversal of the disks through a sequence of antiparallel states. The dynamical properties were studied by Brillouin light scattering and micromagnetic simulations which solve the discretized Landau-Lifshitz-Gilbert equation in the time domain and calculated locally the Fourier transform. The comparison between measurements and simulations allowed us to correlate the field dependence of different modes in each ferromagnetic layer to their localization inside the disk. © 2008 American Institute of Physics.