Metal passivation effect on focused beam-induced nonuniform structure changes of amorphous SiOx nanowire

TL;DR

This study investigates how gold nanoparticle passivation influences the structural changes of amorphous SiOx nanowires under focused electron beam irradiation, revealing a shift from plastic deformation to evaporation-dominated processes.

Contribution

It demonstrates that Au nanoparticle passivation alters the nonuniform structural evolution of SiOx nanowires during electron beam exposure, introducing a new passivation effect.

Findings

AuNPs passivation retards nanowire necking

Structural change shifts from plastic flow to evaporation

Passivation leads to increased nanowire stability

Abstract

Passivation effect of heterogeneous Au nanoparticles (AuNPs) on the nonuniform structure changes of amorphous SiOx nanowire (a-SiOx NW) as athermally induced by focused electron beam (e-beam) irradiation is investigated in an in-situ transmission electron microscope. It is found that at room temperature the straight and uniform a-SiOx NW demonstrates an accelerated necking at the nanoscale along with a fast, plastic elongation and a local S-type deformation in the axial direction. However, once being modified with uniform AuNPs, the nanocurved sidewall surface of a-SiOx NW becomes intriguingly passivated and the processing transfers from a diffusion (or plastic flow)-dominated status to an evaporation (or ablation)-dominated status. As a result, the necking of the AuNPs-modified a-SiOx NW is greatly retarded without visible elongation and bending deformation. Two combined effects of nanocurvature and beam-induced soft mode and instability of atomic vibration are further proposed to elucidate the observed new phenomena.