Spatial resolution in atom probe tomography

TL;DR

This paper develops a methodology to quantify the anisotropic spatial resolution in atom probe tomography, considering factors like crystallography and temperature, and highlights its specimen-specific nature.

Contribution

It introduces an advanced analysis method for measuring both in-depth and lateral resolution in atom probe tomography, addressing previous gaps in standardization.

Findings

Resolution is anisotropic, better in depth than laterally.

Crystallography and temperature influence resolution.

Resolution varies significantly between specimens.

Abstract

This article addresses gaps in definitions and a lack of standard measurement techniques to assess the spatial resolution in atom probe tomography. This resolution is known to be anisotropic, being better in the depth than laterally. Generally the presence of atomic planes in the tomographic reconstruction is considered as being a sufficient proof of the quality of the spatial resolution of the instrument. Based on advanced spatial distribution maps, an analysis methodology that interrogates the local neighborhood of the atoms within the tomographic reconstruction, it is shown how both the in-depth and the lateral resolution can be quantified. The influences of the crystallography and the temperature are investigated, and models are proposed to explain the observed results. We demonstrate that the absolute value of resolution is specimenspecific.