Dynamic Magneto-Optical Imaging of Domains in Grain-Oriented Electrical Steel

Magneto-optical imaging with magneto-optical indicator films (MOIF) is a versatile method to characterize magnetic field distributions especially for material development and quality control. Magnetic domains and grains in grain-oriented electrical steel can be visualized, and quantified without removing the isolation layer. The combination of MOIF with digital high-speed camera technology enables temporally resolved investigations of the magnetization processes. In contrast to Kerr-effect measurements MOIF imaging works without sample preparation and even in the presence of industrial insulation coatings. Optical resolution of 25 microns and temporal resolution of 1 ms in single-shot mode could be demonstrated.