Magnetization reversal in nanostructured Co/Pt multilayer dots and films

We report on the magnetic properties of large scale periodic magnetic nanostructures designed as dot-arrays with periodicity ranging between 300 nm and 1100 nm, consisting of Co/Pt multilayer dots with respective diameters ranging between 230 nm and 740 nm. The nanostructures are fabricated by using optical interference lithography allowing for large area (cm/sup 2/) fabrication. The Co/Pt multilayer dots show a pronounced out-of-plane magnetic anisotropy. The magnetic properties are determined from magneto-optical Kerr effect measurements in polar geometry and results are compared to respective continuous Co/Pt multilayer thin films. The micromagnetic properties of both, films and nanostructures are investigated with magnetic force microscopy allowing for the application of an external perpendicular magnetic field of up to B=0.15 T.