Physical response of gold nanoparticles to single self-ion bombardment

The reliability of nanomaterials depends on maintaining their specific sizes and structures. However, the stability of many nanomaterials in radiation environments remains uncertain due to the lack of a fully developed fundamental understanding of the radiation response on the nanoscale. To provide an insight into the dynamic aspects of single ion effects in nanomaterials, gold nanoparticles (NPs) with nominal diameters of 5, 20, and 60 nm were subjected to self-ion irradiation at energies of 46 keV, 2.8 MeV, and 10 MeV in situ inside of a transmission electron microscope. Ion interactions created a variety of far-from-equilibrium structures including small (∼1 nm) sputtered nanoclusters from the parent NPs of all sizes. Single ions created surface bumps and elongated nanofilaments in the 60 nm NPs. Similar shape changes were observed in the 20 nm NPs, while the 5 nm NPs were transiently melted or explosively broken apart.