Magnetic after-effect spectra analysis by applying the lognormal distribution of relaxation times

An analysis of magnetic after-effect spectra made by applying the gaussian distribution in In tau is presented and discussed in details. The procedure described allows to decompose very broad relaxation spectra into several relaxation processes with continuous distributions of relaxation times. This model is applied to the quantitative analysis of isochronal disaccommodation curves obtained for several amorphous and partially crystallized ribbons of Fe73.5Cu1Nb3Si13.5B9 (after stress relieving at 673 K for Ih and annealing at 823 K for 10 s), Fe87Zr7B6 (in the as-quenched state and after annealing at 700 K for 1 h) and Co66Fe4Mo2Si16B12 (annealed at 700 K for 30 s) alloys. From this analysis the mean activation enthalpy, pre-exponential factors, intensities and widths of the distributions in In tau of individual processes are determined. (C) 1998 Elsevier Science B.V. All rights reserved.