Evolution of magnetostriction in Fe73.5-xNixCu1Nb3Si13.5B9 (x=0, 10, 20, 30, 40) alloy in the course of transformation

Magnetostrictions lambda(parallel to)H, lambda(perpendicular to)H, omega(H), lambda(parallel to), lambda(perpendicular to) and partial derivativeomega/partial derivativeH were studied on the Finemet alloy system Fe73.5-xNixCu1Nb3Si13.5B9. The dependencies lambda(parallel to)H show that they are a superposition of at least two such dependencies originating from two phases with different degree of separation. From the values of lambda(parallel to), lambda(perpendicular to) and omega(H) the As and partial derivativeomega/partial derivativeH values were determined, respectively. Temperature dependencies of As change with the concentration of Ni, decreasing from 25 x 10(-6) to 9 X 10(-6); partial derivativeomega/partial derivativeH follows the internal processes taking place in the transformation. In amorphous state the spontaneous volume magnetostriction and lambda(s) values decrease with increasing Ni content. (C) 2002 Elsevier Science B.V. All rights reserved.