Magnetooptical Visualization and Mapping of Magnetic Stray Fields over the Surface of Composite Permanent Magnets Using Gadolinium–Cobalt Amorphous Films

Abstract

Stray fields of magnetic systems with a known degree of structural and magnetic nonuniformities have been mapped using indicator amorphous films with a perpendicular anisotropy. The characteristic magnetooptical patterns have been determined, which correspond to the distribution of the magnetic-field component normal to the plane of the indicator films. The theoretical patterns of model magnetic systems that are similar to the studied systems in the degree of the structural and magnetic nonuniformity have been calculated. The validity of the magnetooptical visualization has been confirmed by comparison of the experimental and theoretical patterns. The possibility of the express monitoring of the parameters of the magnetic system has been shown using a laboratory model of a magnetooptical visualizer by the observation of the magnetooptical contrast of gadolinium–cobalt indicator films under the action of an ac magnetic field.