The direct observation of domain structure and magnetic fields in the scanning electron microscope

Abstract

A description is given of preliminary work showing the ability of the scanning electron microscope to resolve magnetic surface detail. The magnetic fields influence the secondary electron signal directly so that colloid patterns (Bitter technique) are eliminated and the actual fields, rather than the rate of change of field, determine the picture observed. Micrographs are included showing domain structures on two perpendicular faces of a cobalt crystal, and also a direct observation of recordings on magnetic tape. Apart from its application to the study of magnetic structure, the technique offers a convenient method of very accurate calibration (approaching 0.1% with care) by using a magnetic strip alongside a specimen under observation.