Annealing Effects In Ferromagnetic Amorphous Alloys

摘要

Annealing the ferromagnetic amorphous alloys produces structural relaxation which affects most of the physical properties. The manner with which the annealing affects the property, however, is not the same for all properties. In some cases the effect is irreversible below the glass transition temperature, while in other cases it is clearly reversible. Magnetic properties such as the field induced anistropy, creep-induced anisotropy, Curie temperature, and the permeability disaccommodation DA, are all reversible; they saturate to temperature dependent equilibrium values after some time during annealing, and if the annealing temperature is reversibly changed, they follow the change with some characteristic delay. We have shown that the four magnetic properties listed above and anelasticity measured by internal friction all share the basically same kinetics, and therefore the same microscopic mechanism. By computer simulation and X-ray diffraction, the microscopic mechanism of the reversible relaxation phenomena has been determined to be the local shear deformations which re-orient some of the atomic bombs.