Magnetic domain compensation effect on the magnetodynamic response of ferromagnetic elements

The capacity to tune the ferromagnetic resonance frequency in a soft ferromagnetic film relies on the ability to tailor the uniaxial anisotropy of the film material. We achieved a systematic change in anisotropy field with all other material properties remaining constant by preparing Ni₁₈Fe₁₉/Co₆₀Fe₂₀B₂₀ multilayers. We show that in patterned films deviations from the regular Landau domain pattern occur, which compensate magnetic anisotropy effects and thereby lead to a precessional frequency independent of anisotropy. These results demonstrate that even small changes in the magnetic domain structure counteracts anisotropy adjustments in optimizing the magnetodynamic response in mesoscopic thin film elements.