Atomistic mechanism of solid-state amorphization in the Ni-Zr system revealed by molecular dynamics simulation

Solid-state amorphization in the Ni-Zr system, which has a large negative h eat of formation and a large atomic size difference, has been studied by mo lecular dynamics simulation. Simulation results demonstrated that atomic di ffusion took place prior to amorphization in a temperature range from 250 t o 600 degrees C. Quantitatively, amorphization is governed by a diffusion-l imited reaction with an asymmetric growth exactly following a t(1/2) law. B esides, a low temperature limit allowing solid-state amorphization is found ro be about 250 degrees C.