Three-dimensional description of vibration-assisted electron knock-on damage

TL;DR

This paper develops a comprehensive three-dimensional model of electron knock-on damage in metals, accounting for atomic vibrations and temperature, to better predict damage mechanisms and rates.

Contribution

It introduces a full 3D theory of knock-on damage that includes out-of-plane vibrations and temperature effects, extending previous models limited to in-plane considerations.

Findings

In-plane nitrogen atom jumps suggest stronger inelastic effects than in pristine graphene.

The model accurately describes electron irradiation effects through elastic scattering.

Temperature and vibrations significantly influence damage cross-sections.

Abstract

Elastic knock-on is the main electron irradiation damage mechanism in metals including graphene. Atomic vibrations influence its cross-section, but only the out-of-plane direction has been considered so far in the literature. Here, we present a full three-dimensional theory of knock-on damage including the effect of temperature and vibrations to describe ejection into arbitrary directions. We thus establish a general quantitative description of electron irradiation effects through elastic scattering. Applying our methodology to in-plane jumps of pyridinic nitrogen atoms, we show their observed rates imply much stronger inelastic effects than in pristine graphene.