TEM, HREM, L-TEM Studies of Fe-Based Soft Magnetic Melt-Spun Ribbons Subjected to Ultra-Rapid Annealing Process

Abstract

To uLTRa-Rapid annEaLing pRocESS in the present work, we performed the ultra-rapid annealing (ura) process for amorphous Fe 78 ni 8 B 14 melt-spun ribbons in order to obtain fine excellent microstructure assuring the best soft magnetic properties. several microscopic methods mainly based on transmission electron microscopy (teM) and lorentz teM (l-teM) were applied for detailed studies of the microstructure and magnetic domains structure. the investigation revealed that the optimized parameters of the uRA process (500°C/0.5-5 s) lead to outstanding soft magnetic properties. A mixture containing close to 50% amorphous phase and 50% α-Fe nanocrystals of size up to 30 nm has been already obtained after annealing for 3 s. these annealing conditions appear to be the most suitable in terms of microstructure providing the best magnetic properties.