Bubble lattice formation in a magnetic uniaxial single-crystal thin plate

Abstract

Experimental evidence which may give a solution to the puzzling problem of the contradiction between micromagnetic predictions and experiments on the domain nucleation mode in a thin plate with uniaxial easy axis perpendicular to the plane is reported. It is very likely that a honeycomb structure or a bubble lattice in a remanent state is a result of stripe domain pinching, not an indication of a domain nucleation mode as has generally been speculated. The behavior of domains near saturation when a field is inclined at an arbitrary angle was observed in detail. It was found that a bubble lattice was formed near saturation through a stripe domain pinching for a wide range of the angle between the applied field and the easy axis. Only in a narrow range of this angle do the bubbles survive into a demagnetized state to form a lattice. Furthermore, the domain structures that appear first during demagnetization are not like those of micromagnetic predictions at any intermediate angle of the field between the easy axis and the plane of the sample. They seem rather a result of the initial domain formation at the edges of the sample.