Structure and magnetic behaviour of Fe–Cu–Nb–Si–B–Al alloys

Abstract Fe was substituted by Al up to 7 at% in Finemet. After annealing at 550°C all samples were nanocrystalline, with more or less ordered α-Fe(Si,Al) grains; the DO3-like ordering was the most dominant in samples with 5 and 7 at% of Al. In as-quenched state Al decreased linearly the magnetization, but up to 3 at% enhanced the Curie temperature of the alloy. The Curie temperature of the crystalline phase and the magnetization in annealed samples abruptly decreased, when there was more than 5 at% of Al in the alloy.