DOMAIN-STRUCTURE CHANGES IN A FERROMAGNETIC CO90HF10 METALLIC-GLASS

This paper presents a study of the thermal changes in the domain structure of a Co//9//0Hf//1//0 amorphous alloy. Melt-spun specimens were isothermally annealed under high vacuum at 700 K for 2 and 4 h and confirmed to have remained amorphous. A Philips EM 301 transmission electron microscope working in the Lorentz mode (LTEM) and Fresnel contrast was used to study the domain structures. In the as-quenched alloy ripple structures observed, the alloy annealed for 2 h and the ripple structure gradually disappeared, with a tendency to form a stripe pattern originating from the main domain walls. Finally, in the alloy annealed for 4 h, stripe structures were formed, consisting mostly of Bloch walls. The observed changes in the domain patterns are discussed in terms of the domain energy.