Imaging individual solute atoms at crystalline imperfections in metals

TL;DR

This paper introduces an advanced imaging technique combining FIM, DFT, and mass spectrometry to directly visualize individual solute atoms at crystalline defects in metals, providing atomic-level insights into material properties.

Contribution

The paper presents a novel analytical-FIM method with true atomic resolution that can identify individual solute atoms at specific microstructural sites in metals.

Findings

Re atoms identified at crystalline defects in Ni during creep

Direct comparison of experimental results with atomistic simulations

Insights into Re's role in extending Ni-based superalloy lifetime

Abstract

Directly imaging all atoms constituting a material and, maybe more importantly, crystalline defects that dictate materials' properties, remains a formidable challenge. Here, we propose a new approach to chemistry-sensitive field-ion microscopy (FIM) combining contrast interpretation from density-functional theory (DFT) and elemental identification enabled by time-of-flight mass-spectrometry and data mining. Analytical-FIM has true atomic resolution and we demonstrate how the technique can reveal the presence of individual solute atoms at specific positions in the microstructure. The performance of this new technique is showcased in revealing individual Re atoms at crystalline defects formed in Ni during creep deformation. The atomistic details offered by A-FIM allowed us to directly compare our results with simulations, and to tackle a long-standing question of how Re extends lifetime of Ni-based superalloys in service at high-temperature.