Abstract
The magnetic aftereffect and its dependence on annealing have been measured in a zero magnetostrictive Fe4.7Co70.3Si15B10 amorphous alloy. The relaxation strength depends sensitively on the magnetizing ac field amplitude. It also depends on annealing temperature and time in a complex manner. There is a critical field at which the permeability changes abruptly. This field corresponds to the unpinning (stabilization) field of domain walls. The observed behavior can be explained in terms of two main processes: the irreversible stress relaxation and the reversible changes in short range order associated with the local induced anisotropy.