Modeling the heterogeneity response induced by the cascade collisions of glass-ceramics

Abstract

An effective molecular dynamics model to describe heterogeneous materials like glass-ceramics is proposed. Based on the model, we find that the velocity direction of the primary knock-on atom (PKA) is more prone to deflect sharply in glassy phases (GP) than that in crystalline phases (CP). And the high-stress region in CP is more concentrated, while the distribution of the high-stress region in GP is relatively discrete. Typical topologies of the Frenkel pairs (FPs) show that the direction of FPs propagation has an obviously turn at the boundary. In the hot peak period, the off-site atoms induced by the cascade collisions in CP could rearrange to avoid the number of defects coming to a high point. However, once the distorted clusters form in GP, the dislocated atoms of the distorted clusters are hard to move back to their site due to the high energy barriers. The annihilation of defects is also blocked in GP. The derived results could help to further understand the evolution mechanism of the heterostructure and defects at the nanoscale. And the method of model construction could contribute to more exciting simulations.