Effects of atom–electron energy exchange on radiation damage in zirconium

Abstract

Molecular dynamics (MD) is an important tool for investigating primary radiation damage in materials. Electronic effects, including electronic stopping power (se) and electron–phonon coupling (EPC), have a significant influence on high-energy radiation damage in many metals. Based on MD, this study investigated the role played by electronic effects on the collision cascade in α-zirconium (α-Zr). The results show that when the dominant type of cascades is unconnected subcascades, EPC obviously affects the evolution of collision cascades. The incorporation of EPC can promote the generation of subcascades, which reduces large defect clusters. Furthermore, more defects survive when EPC is applied, where the number of residual defects increases with the capacity of EPC. In contrast, the application of se on low-energy atoms impels the aggregation of the defects into large clusters. However, both EPC and se only slightly affect the spatial distribution of the defect clusters. The influence of cutoff energy choice on the simulation results was also discussed.

Keywords

• Molecular dynamics
• Electronic effects
• Radiation damage
• α-Zirconium