Atomistic simulation of defect-induced amorphization of binary lattices

Abstract

Crystal-to-amorphous transitions are studied by molecular-dynamics simulations in which self-interstitials are randomly and sequentially inserted into solids composed of two atomic species with size difference of 20%. Lennard-Jones interatomic potentials are used for the simulations at finite temperature (about (1/4 melting) and constant pressure (P=0). Two initial structures are considered, an $A_3$B ordered lattice and an AB solid solution which is significantly disordered. A variety of physical properties are evaluated to assess the effects of the interstitial insertions and subsequent system relaxation. Results provide atomistic details which point to the dominant role of chemical ordering in the amorphization process; they also reveal, in quantitative terms, the essential difference between the amorphization of binary systems and that of single-component lattices studied previously.