Athermal glass work at the nanoscale: Engineered electron-b eam-induce d viscoplasticity for mechanical shaping of brittle amorphous silica

Amorphous silica deforms viscoplastically at elevated temperatures, which is common for brittle glasses. The key mechanism of viscoplastic deformation involves interatomic bond switching, which is thermally activated. Here, we precisely control the mechanical shaping of brittle amorphous silica at the nanoscale via engineered electron-matter interactions without heating. We observe a ductile plastic deformation of amorphous silica under a focused scanning electron beam with low acceleration voltages (few to tens of kilovolts) during in-situ compression studies, with unique dependence on the acceleration voltage and beam current. By simulating the electron-matter interaction, we show that the deformation of amorphous silica depends strongly on the volume where inelastic scattering occurs. The electron-matter interaction via e-beam irradiation alters the Si-O interatomic bonds, enabling the high-temperature deformation behavior of amorphous silica to occur athermally. Finally, by systematically controlling the electron- matter interaction volume, it is possible to mechanically shape the brittle amorphous silica on a small scale at room temperature to a level comparable to glass shaping at high temperatures. The findings can be extended to develop new fabrication processes for nano- and microscale brittle glasses.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates the precise mechanical shaping of brittle amorphous silica by controlling electron-matter interactions. The deformation of amorphous silica is achieved through electron beam irradiation, which alters the Si-O interatomic bonds and enables high-temperature deformation behavior to occur athermally. This research opens up new possibilities for fabricating nano- and microscale brittle glasses.