The magnetic domain structure of monocrystalline Co2Y

The domain structure of single crystals of the hexagonal ferrite Co₂Y (Ba₂Co₂Fe₁₂O₂₂ ) with planar anisotropy has been studied with the Bitter technique. The results are consistent with the existence of large area domain walls parallel to the easy plane. The domain spacing accords with a previous theoretical model. No domain structure is visible on the basal plane. The authors have followed the magnetization process from studies on axial samples. On reducing from saturation 360° walls are first nucleated; these then split into reversed domains with 180° walls which move independently. A converse behavior is observed as the field is reversed and increased to saturation in the opposite sense