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

Magneto-impedance and Delta E measurements of amorphous wires having t he compositions Fe77.5Si10B15 and in the as-quenched and annealed stat es are presented. The results are interpreted in the light of the wide ly accepted core-shell domain models for positively and negatively mag netostrictive amorphous wires respectively. It is concluded that in wi res 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. I n wires of Co72.5Si12.5B15 significant circumferential anisotropy is i nferred in all states of annealing studied.