Self-organized plane arrays of metallic magnetic elements
  We studied the dynamic magnetic properties of plane periodical arrays of circular permalloy nano-dots fabricated using a self-organized mask formed by polysterene nanospheres on the surface of a Permalloy film. Conventional (microwave cavity) and broadband coplanar-line ferromagnetic resonance setups were used for the measurements. We found several well resolved resonance peaks. This result shows that the self-organized mask fabrication technique is able to produce high-quality samples with small dispersion of geometrical and magnetic parameters. 
M. Kostylev, R.Magaraggia, F.Y. Ogrin, V. Mescheryakov, N. Ross, and   R.L. Stamps