Resonance modes in arrays of interacting ferromagnetic nanowires subjected to a transverse static magnetic field

We report the measurement and modeling of two ferromagnetic resonance (FMR) modes in an array of amorphous CoFeB ferromagnetic nanowires with the applied static magnetic field transverse to the nanowire axes. The two modes are observed below saturation and are excited independently by the components of the microwave magnetic field parallel and perpendicular to the static field. We model the magnetization dynamics of the array as arising from the response of two interacting populations of wires magnetized mirror-symmetrically to each other relative to the plane of the array. The theory is well supported by experimental results obtained from vibrating sample magnetometer and shorted waveguide FMR measurements. (C) 2011 American Institute of Physics. [doi:10.1063/1.3564906]