Passivation Effect of Gold Nanoparticles on Uniform Beam-Induced Structural Changes of Amorphous SiOx Nanowire

Abstract

The reshaping of amorphous SiOx nanowires (a-SiOx NWs) as purely induced by uniform electron beam (e-beam) irradiation was in-situ studied at room temperature in transmission electron microscope. It was observed that the axially straight NW kept its perfect straight cylinder-like wire shape and demonstrated a sequential uniform radial shrinkage with the increase of irradiation time. In contrast, the axially curved NW turned straight quickly accompanied with a uniform axial shrinkage and a uniform radial expansion intriguingly. It is expected that such a study especially on the straightening of axially curved NW has important implications for the nanoscale processing and stability of future NW-based structures or devices. More importantly, the findings demonstrate that the traditional knock-on mechanism and electron beam heating effect are inadequate to explain these processes while our proposed nanocurvature effect and energetic beam-induced athermal activation effect obviously dominate the processes.