Effect of thermal treatments on the magnetic inhomogeneities distribution in magnetic amorphous wires and microwires

Positive magnetostrictive Fe77.5Si7.5B15 conventional amorphous wires (CAW) 125 mum in diameter and amorphous glass-covered microwires (AGCW) with the metallic core diameter of 35 mum have been annealed below and above their crystallization temperature, which produces the precipitation of alpha-Fe(Si) phase within the amorphous matrix. The J-H loop and the temperature dependence of the magnetization and the coercive held reveal the presence of two different magnetic phases in the thermally treated samples. The effect of the thermal treatments on the magnetic domain structure in both CAW and AGCW and its influence on their soft magnetic properties is discussed.