EFFECTS OF CRYSTALLIZATION ON MAGNETIC DOMAIN-STRUCTURE OF AMORPHOUS FE78B13SI9 ALLOY

A transmission electron microscope study of the interrelation between microstructure and magnetic domain configuration in the alloy Fe78B13Si9 both in as-quenched and crystallized states has been made. A preliminary investigation of the interaction of the domain walls with crystals formed during partial crystallization has also been made. The domain structure in the as-quenched state consists of large domains in which magnetization directions are determined mainly by magnetostatic effects. The onset of crystallization is accompanied by a considerable refinement of the domain size. As the specimen approaches complete crystallization, the domain structure becomes increasingly complex. In situ applied field experiments demonstrate that the crystallization products act as pinning sites for domain walls.