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

Abstract Magnetostrictions λ ∥ H , λ ⊥ H , ω ( H ), λ ∥ , λ ⊥ and ∂ ω /∂ H were studied on the Finemet alloy system Fe 73.5− x Ni x Cu 1 Nb 3 Si 13.5 B 9 . The dependencies λ ∥ 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 λ ∥ , λ ⊥ and ω ( H ) the λ S and ∂ ω /∂ H values were determined, respectively. Temperature dependencies of λ S change with the concentration of Ni, decreasing from 25×10 −6 to 9×10 −6 ; ∂ ω /∂ H follows the internal processes taking place in the transformation. In amorphous state the spontaneous volume magnetostriction and λ S values decrease with increasing Ni content.