Magnetic domain demonstrations using the kerr magneto-optic effect

Abstract

A new approach to the teaching of magnetic materials is afforded by a new teaching aid; the teaching aid enables magnetic domain changes for d.c. and a.c. magnetization to be shown on a television screen to large groups of students, demonstrating phenomena such as coercivity, remanence, hysteresis and saturation. Barkhausen noise is heard, accompanying the domain wall movements. Magnetostriction is demonstrated using a signal from a double piezo-electric transducer placed under the specimen, and the effects of longitudinal stress on all the above phenomena can be observed simultaneously.