Microwave permeability of Y-type hexaferrites in zero and low fields

Abstract We have investigated the zero field permeability of Y-type Hexaferrites. In this paper, the measured permeability of Ba2MnZnFe12O22 from 0.045 to 10 GHz was theoretically explained in terms of zero magnetic field multi-domain and wall resonances. The basal plane anisotropy field HφA, domain wall thickness δ and length L of the domain wall was estimated from resonance and permeability data. The HφA was also confirmed from the in plane FMR, and shape effects were readily estimated from permeability measurements.