Magnetic multi-domain resonance in single crystal ferrite platelets

We have observed ferromagnetic resonance (FMR) on single crystal platelets of Zn and Co substituted M-type hexagonal ferrites. FMR was observed with both swept field and swept frequency measurements. The results were compared, and agreed well, with calculations of resonance frequencies based on periodic arrays of stripes and bubble domains. In addition to the resonance parameters necessary to describe the results in the magnetically saturated regime, our calculations take into account the wall energy, which results in a field dependence of the domain spacing, which in turn strongly affects the resonances near saturating fields.