Nucleation of the Honeycomb Domain Structure

Abstract

Thin platelets of magnetoplumbite exhibit a characteristic honeycomb domain structure upon demagnetization in a field lying in or near the plane of the platelet. The nucleation of such a domain structure is difficult to understand on the basis of standard domain theory because it has been shown that its free energy is larger than that of a structure of parallel strip domains. It is shown that the formation of the pattern can be accounted for by a combination of micromagnetics and domain theory. The theory predicts that the nucleated pattern is either (H inclined to the crystal plane) a checkerboard pattern or (with H parallel to the crystal plane) a parallel strip pattern which becomes unstable with respect to certain distortions. In either case the pattern can be genetically related to the resulting honeycomb pattern. On the basis of comparison with experimental findings reported in the literature, an estimate can be made of the range of validity of standard domain theory near magnetic saturation.