DSC studies of finemet-type glass-coated microwires

Effect of cyclic annealing on the Curie temperature, T-C, of Fe71.8Cu1Nb3.1Si15B9.1 glass-coated microwires has been investigated. T-C of the initially amorphous alloy strongly depends on annealing conditions. Monotonic increase of T-C from 579 up to 591 K related with the relaxation of amorphous structure was found during annealing at 633 K. After a certain annealing time in the temperature range 713-813 K, T-C splits into two Curie temperatures with values higher (T-C1) and lower (T-C2) than that of the initial state. Further increase of the annealing time, t(ann), tends to increase T-C1 and decrease T-C2. Such peculiar behavior is related with the decomposition of the amorphous matrix and the beginning of the devitrification process. (C) 2002 Elsevier Science B.V. All rights reserved.