Solid-state amorphization in Ni/Nb mutilayers studied by molecular-dynamics simulation together with experiments

Based on an embedded-atom method, an n-body potential is developed for the Ni-Nb system and the potential is then applied in molecular-dynamics simulation to study the detailed process of interfacial reaction in an Ni-Nb sandwich model. It turns out that the solid-state amorphization is initiated by interface-crossing atomic migration and governed by diffusion-limited reaction in the Ni-Nb system characterized by a negative heat of formation. The simulation results are confirmed by thermal annealing experiments conducted at medium temperatures.