Molecular dynamics simulation and first principles calculations of radiation-induced Cu clusters in Fe-3 at.% Cu alloy

Molecular dynamics (MD) simulations of displacement cascades in Fe-3 at.% Cu alloy were carried out with various primary knocked-on atom (PKA) energies at different temperature. The results showed that if PKA energy was lower than 20 keV, no stable clusters of Cu was found. However, when energy equaled to 20 keV, Cu cluster containing seven Cu atoms was found and Cu cluster could be stabilized after 5 ps. MD simulations and first principles calculations showed that irradiation-induced vacancies played a key role in the formation of the Cu cluster, and Cu atoms congregation decreased the energy of systems.