Structural relaxation and viscosity in Co-based amorphous materials

Abstract The variation of viscosity of Co 69 B 12 Si 12 Fe 4 Mo 2 Ni 1 and Co 70 Si 14 B 9 Mn 5 Fe 1 Mo 1 amorphous materials with isothermal and isochronal annealing has been obtained. The results show that there is an increase of the viscosity as the temperature and the time of the thermal annealing increase. This behaviour is explained as a consequence of the structural relaxation of these materials due to their metastable condition in the as-quenched state. The annealing process produces changes in the topological short range order and in the chemical short range order.