Structural modification of a multiply twinned nanoparticle by ion irradiation: A molecular dynamics study

We study the possibility of modifying the structure of a multiply twinned nanoparticle by ion irradiation. Molecular dynamics simulations are carried out for the prototypic case of a metastable icosahedral Pt particle bombarded with He and Xe ions in the energy range of 0.1 - 10 keV . A single xenon impact can be used to melt the particle. It can also induce partial melting, which causes a collapse of the twin boundary structure in the solid part and transformation to single crystalline morphology. Under He irradiation, we observe a saturation of the vacancy concentration, but no untwinning.