Effects of stress on the magnetization of Fe80B20 and Fe73.5Cu1Nb3Si15.5B7 amorphous alloys

The influence of torsion (tau less than or equal to 30 pi/m) and tensile stress (sigma less than or equal to 45 MPa) on the process of magnetization and the domain structure of as-quenched amorphous Fe80B20 and Fe73.5CU1Nb3Si15.5B7 alloys has been studied by means of the direct (J(D)) and alternating (J) currents following along the ribbon. The application of the model for the influence of field H-p, generated by the core current, on the process of magnetization (the dM/dt vs. H curves and the M-H loops) shows that torsion increases both the average angle [delta] between the magnetizations (I) of the domains participating in the process of magnetization and the ribbon axis and the strength [S-u] of the domain wall pinning centers within the ribbon, whereas the tensile stress reduces both [delta] and [S-n]. Initially both stresses increase the maximum magnetization M-m0 (at the given field amplitude H-0) which implies that sizable fraction of domains does not contribute to magnetization along the ribbon axis in the unstressed state. This provides an insight into the magnetic properties of the as-quenched magnetostrictive ribbons in the unstressed state.