Atom probe tomography: a local probe for chemical bonds in solids

TL;DR

This paper explores the use of atom probe tomography as a local technique to analyze chemical bonds in solids, distinguishing different bond types based on bond rupture behavior and providing insights into material design.

Contribution

It demonstrates that atom probe tomography can differentiate metallic, covalent, and metavalent bonds by analyzing bond rupture processes, introducing the concept of bonding probe tomography.

Findings

Solid types can be distinguished by PME and PMI values.

Differences in field penetration depth explain bond rupture variations.

The approach enables nanometer-scale bond quantification.

Abstract

Atom probe tomography is frequently employed to characterize the elemental distribution in solids with atomic resolution. Here we review and discuss the potential of this technique to locally probe chemical bonds. Two processes characterize the bond rupture in laser-assisted field emission, the probability of molecular ions, i.e. the probability that molecular ions (PMI) are evaporated instead of single (atomic) ions, and the probability of multiple events, i.e. the correlated field-evaporation of more than a single fragment (PME) upon laser- or voltage pulse excitation. Here we demonstrate that one can clearly distinguish solids with metallic, covalent, and metavalent bonds based on their bond rupture, i.e. their PME and PMI values. Differences in the field penetration depth can largely explain these differences in bond breaking. These findings open new avenues in understanding and designing advanced materials, since they allow a quantification of bonds in solids on a nanometer scale, as will be shown for several examples. These possibilities would even justify calling the present approach bonding probe tomography (BPT).