The relaxation of internal stresses during annealing of amorphous Fe 40Ni 40B 20

Abstract

Because of the magneto-elastic coupling, the magnetic domain structure of amorphous materials is mainly determined by the local stress state. The stress dependence of the domain structure therefore contains important information on the internal stress distribution in the material. The three-dimensional neutron depolarization technique was used to study the stress dependence of the bulk domain structures in as-quenced and annealed Fe 40Ni 40B 20. A three-layer domain structure model corresponding to compressive and tensile internal stresses is presented to explain the measured data. Using this model, the average magnitude of the internal stresses could be followed as a function of the annealing treatment. A comparison is made between the kinetics of stress relaxation and the structural relaxation effects.