A model to predict image formation in the three-dimensional field ion microscope

TL;DR

This paper introduces a numerical model for simulating image formation in 3D field ion microscopy, aiding in the accurate reconstruction of atomic-scale defects in materials.

Contribution

It combines a meshless evaporation algorithm with field ionization physics to simulate imaging artifacts caused by non-regular evaporation and atomic perturbations.

Findings

Simulates imaging artifacts due to irregular evaporation.

Models impact of atomic perturbations near defects.

Enhances 3DFIM accuracy for defect analysis.

Abstract

This article presents a numerical model dedicated to the simulation of field ion microscopy (FIM). FIM was the first technique to image individual atoms on the surface of a material. By a careful control of the field evaporation of the atoms from the surface, the bulk of the material exposed, and, through a digitally processing a sequence of micrographs, a three-dimensional reconstruction can be achieved. 3DFIM is particularly suited to the direct observation of crystalline defects such as vacancies, interstitials, vacancy clusters, dislocations, and any combinations of theses defects that underpin the physical properties of materials. This makes 3DFIM extremely valuable for many material science and engineering applications, and further developing this technique is becoming crucial. The proposed model enables the simulation of imaging artefacts that are induced by non-regular field evaporation and by the impact of the perturbation of the electric field distribution of the distorted distribution of atoms close to defects. The model combines the meshless algorithm for field evaporation proposed by Rolland et al. (Robin-Rolland Model, or RRM) with fundamental aspects of the field ionization process of the gas image involved in FIM.