MAGNETO-IMPEDANCE AND DELTA-E MEASUREMENTS OF IRON-BASED AND COBALT-BASED AMORPHOUS WIRES

Magneto-impedance and Delta E measurements of amorphous wires having the compositions Fe77.5Si10B15 and in the as-quenched and annealed states are presented. The results are interpreted in the light of the widely accepted core-shell domain models for positively and negatively magnetostrictive amorphous wires respectively. It is concluded that in wires of Fe77.5Si10B15 the radial easy axi structure in the shell of the as-quenched wire weakens after light annealing, eventually giving way to a circumferential structure when surface crystallization occurs. In wires of Co72.5Si12.5B15 significant circumferential anisotropy is inferred in all states of annealing studied.