Stress dependence of the saturation magnetostriction in Co68.15Fe4.35Si12.5B15 glass-covered amorphous wires

The influence of stress current annealing on the saturation magnetostriction for Co(68.15)Fe(4.35)Si(12.5)B(15) glass-covered amorphous wires having 21.3 mum diameter of the metallic core and 7 mum thickness of the glass cover with and without glass cover is presented. The obtained results show that in the as-cast state the values of saturation magnetostriction at zero applied stress, lambda(s)(0), and stress derivative, alpha, are about -0.11 X 10(-6) and -0.9 x 10(-10) MPa(-1), respectively, for glass cover samples and -0.05 x 10(-6) and -1 x 10(-10) MPa(-1), respectively, for glass removed samples. After about 3-8 min stress current annealing, lambda(s)(0) changes from small negative to small positive values. For samples without glass cover lambda(s)(0)(max) is about 1.5 times higher than for samples with glass cover. (C) 2002 Elsevier Science B.V. All rights reserved.