Abstract

The evolution from the amorphous to natiocrystalline state in Fe73.5Si13.5B9Cu1Nb3 amorphous wires has been studied by means of high-frequency magnetoirnpedance (MI) effect, using driving frequencies ranging from 0.1 to 500 MHz. A furnace isothermal annealing has been employed to nanocrystallize the wires (1 h at 565 degrees C in an argon atmosphere), while other samples were annealed at lower temperatures (300, 400 and 475 degrees C during 1 h), in order to evaluate the influence of annealing temperature on the MI effect. The MI response is modified by the influence of both the applied bias field and the driving frequency on the Current distribution ill the samples. (c) 2005 Elsevier B.V. All rights reserved.