Resonance frequency of ferromagnetic thin film controlled by rectangle antidot arrays

Fe₆₆Co₁₇B₁₆Si₁ amorphous thin films containing magnetic antidot lattices with rectangle antidot side were fabricated on silicon substrate by photolithography, DC magnetron sputtering, and lift-off patterning. The presence of antidots destroyed the pristine uniaxial anisotropy in continuous film and brought the multipeak resonant out in microwave permeability. With the increasing thickness of the film, the domain structure and magnetic moment configuration changed so that the peak value became gradually small and even disappear. These changes is attributed to the antidots not only changed the demagnetizing field in test but also in the sputtering deposition. Results also show that the coercive field was increased by the presence of antidots while the hysteresis loop depended more on the geometrical shape of the antidots.