Damage of low-energy ion irradiation on copper nanowire:molecular dynamics simulation

Physical and chemical phenomena of low-energy ion irradiation on solid surfaces have been studied systematically for many years,due to the wide applications in surface modification,ion implantation and thin-film growth.Recently the bombardment of nano-scale materials with low-energy ions gained much attention.Comared to bulk materials,nano-scale materials show different physical and chemical properties.In this article,we employed molecular dynamics simulations to study the damage caused by low-energy ion irradiation on copper nanowires.By simulating the ion bombardment of 5 different incident energies,namely,1 keV,2 keV,3 keV,4 keV and 5 keV,we found that the sputtering yield of the incident ion is linearly proportional to the energies of incident ions.Low-energy impacts mainly induce surface damage to the nanowires,and only a few bulk defects were observed.Surface vacancies and adatoms accumulated to form defect clusters on the surface,and their distribution are related to the type of crystal plane,e.g.surface vacancies prefer to stay on(100) plane,while adatoms prefer(110) plane.These results reveal that the size effect will influence the interaction between low-energy ion and nanowire.