A Comparison of Magnetic Domain Images Using a Modified Bitter Pattern Technique and the Kerr Method on Grain-Oriented Electrical Steel

Differences in the magnetic domain patterns of high permeability grain-oriented (HGO) electrical steel have been compared using a modified Bitter technique and the magneto-optical Kerr method. Distinct differences in the domain images were observed which have been attributed to the greater sensitivity of the Bitter technique to the degree of misorientation of the crystal grains. Electron backscatter diffraction (EBSD) analysis was also carried out to confirm the degree of crystal misorientation for the area under investigation. The results show that the Bitter technique is most effective in detecting the presence of low angle grain boundaries but less accurate than the Kerr method for determining the absolute direction of magnetization.