Ni80Fe20 film with periodically modulated thickness as a reconfigurable one-dimensional magnonic crystal

Magnonic crystals with periodically modulated thickness were fabricated using deep ultraviolet lithography by covering Ni80Fe20 nanowire arrays with continuous Ni80Fe20 film. It is shown that the magnetization reversal and ferromagnetic resonance fields can be tuned either varying the film thickness (t) or the stripe width (w). For t ≥ 20 nm, two different stable magnetic configurations in zero external field were obtained. These configurations are characterized by noticeably different frequencies of ferromagnetic resonance up to 1 GHz and can be switched by applying magnetic pulses of proper amplitude and polarity.