Influence of the surface on magnetic domain-wall microstructure

Abstract

The magnetization orientations in domain walls at the surfaces of an Fe crystal, a ferromagnetic glass, and a Permalloy film, measured by scanning electron microscopy with polarization analysis, exhibit asymmetric surface N\'eel wall profiles which (1) are at least twice as wide as interior Bloch walls in bulk and (2) are described quantitatively by our micromagnetic calculations without assuming any special surface parameters. Misinterpretation of domain-wall widths, Bitter patterns, and magnetic-force-microscopy images can result from overlooking the extreme effect of the surface on magnetic microstructure.