7th NFAPT Annual Lecture
François Vurpillot
Groupe de Physique des Matériaux,
Université et INSA de Rouen, France
Beyond Atom Mapping in Atom Probe Tomography
François Vurpillot is Professor at the University of Rouen Normandie and a researcher in the CNRS laboratory 'Groupe de Physique des Matériaux,'. He serves as the head of the Scientific Instrumentation Department. With a PhD from Rouen and post-doctoral research in Oxford, where he held a Marie Curie Fellowship, he focused on image formation with the APT instrument. Specializing in field emission and laser-induced field emission, he is a world expert in understanding the physical aspects of image formation in APT. His contributions include pioneering modeling approaches and involvement in the development of multiple generations of Atom Probe Instruments. He authored or co-authored to more than 150 publications in the field and several books and book chapters. He was elected President of the International Field Emission Society in 2021.
Abstract
Atom Probe Tomography (APT) enables routine 3D mapping of the elemental composition of a specimen at the (sub)nanometer scale across a growing range of material systems. APT data consist of the spatial coordinates of analyzed atoms combined with elemental identification derived from time-of-flight mass spectrometry. For decades, efforts to improve APT instrumentation have focused on achieving higher spatial precision, mass resolution, and detection efficiency—pursuing the ideal of perfectly reconstructing small material volumes. However, APT still lacks key information needed for a complete understanding of the material: it provides elemental, but not detailed chemical information. Since APT analyzes atoms as individual ions stripped from their bonding environment, it does not normally reveal how atoms are bonded or chemically arranged. Nevertheless, some indirect insights into the material's chemistry can be drawn by examining the field evaporation mechanism—the process by which atoms are removed from the specimen. It has long been known that field evaporation varies with the local atomic environment, suggesting links to the material's underlying chemistry. In this presentation, we show that energetic information related to the field evaporation process is encoded in the mass spectra. These signals reflect strengths of the atomic bounds, which in turn are influenced by the chemical environment. We demonstrate that this vestige energetic information can be spatially mapped with nanometric resolution in several experimental examples, offering a new path to extracting local chemical signatures from APT data [1,2,3].
Keywords: APT, instrumentation, microscopy, field evaporation.
References
- Jean-Baptiste Maillet, et al., Journal of Physics D: Applied Physics, DOI 10.1088/1361-6463/ade690
- François Vurpillot, et al. , Crystallographic Dependence of Field Evaporation Energy Barrier in Metals Using Field Evaporation Energy Loss Spectroscopy Mapping, Microscopy and Microanalysis, Volume 30, Issue 6, December 2024, Pages 1091–1099, https://doi.org/10.1093/mam/ozae083
- Rousseau, et al. Introducing field evaporation energy loss spectroscopy. Commun Phys 6, 100 (2023). https://doi.org/10.1038/s42005-023-01203-2