Uniform e-beam irradiation-induced athermal straightening of axially curved amorphous SiOx nanowires

Abstract

The reshaping of amorphous SiO_x nanowires (a-SiO_x NWs) as solely induced by uniform electron beam (e-beam) irradiation was in situ studied at room temperature using transmission electron microscopy. It was observed that the axially straight NW kept its perfect straight cylinder-like wire shape and demonstrated a uniform radial shrinkage with the increase of irradiation time. In contrast, the axially curved NW quickly became straight accompanied by uniform axial shrinkage and uniform radial expansion. It is expected that such a study in particular on the athermal straightening of axially curved NW has important implications for nanoinstability and nanoprocessing of future NW-based structures or devices. More importantly, the findings demonstrate that the traditional knock-on mechanism and e-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.