Barkhausen noise in soft amorphous magnetic materials under applied stress

We report experimental measurements of Barkhausen noise on a Fe64Co21B15 amorphous alloy under tensile stress. We interpret the scaling behavior of the noise distributions in terms of the depinning transition of the domain walls. We show that stress induced anisotropy enhances the effect of short-range elastic interactions that dominate over long-range dipolar interactions. The universality class is thus different from the one usually observed in Barkhausen noise measurements and is characterized by the exponents tau similar or equal to 1.3 and alpha similar or equal to 1.5, for the decay of the distributions of jump sizes and durations. (C) 1999 American Institute of Physics. [S0021-8979(99)53508-1].