The Barkhausen Effect

Publisher Website
Google Scholar
Abstract
A critical examination is made of the elementary processes which are usually considered as responsible for the discontinuous and irreversible domain boundary movements associated with the Barkhausen effect. The domain structure of an iron-like crystal is considered and it is shown that, of the processes investigated, the only mechanism which will produce discontinuities of the observed order of magnitude and which will result in a hysteresis curve of the usual type, is one in which the movement of a limited section of a 180° domain boundary is delayed by a non-magnetic inclusion whose cross-sectional dimensions are of the same order as the boundary thickness and lie within the range 1 to 2 x 10-5 cm. Inclusions below a critical size (~10-5 cm) will be associated only with reversible effects; the energy associated with larger inclusions (>10-4 cm) will be reduced by the presence of subsidiary domain structures and the associated discontinuous boundary movements will be negligibly small. An explanation of the general form of the experimental results is given and it is suggested that any reduction in the hysteresis loss in ferromagnetic materials can best be brought about by the selective reduction of the number of inclusions whose size is within the critical range.

This publication has 6 references indexed in Scilit: