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MM: Fachverband Metall- und Materialphysik

MM 37: Topical Session Modern Atom Probe Tomography I - Fundamentals

MM 37.1: Topical Talk

Mittwoch, 28. März 2012, 15:00–15:30, H 0107

A modelling approach to understand and improve image formation in Atom Probe Tomography — •François Vurpillot, Maria Gruber, Gérald Da Costa, Alain Bostel, and Bernard Deconihout — Groupe de Physique des Matériaux, UMR CNRS 6634, Université de Rouen, BP 12 , 76801 Saint Etienne Du Rouvray, France

The understanding of image formation in Atom probe Tomography is the direct consequence of the processes of field evaporation, emission and projection of ionised atoms from the Muller field emitter (a sharply pointed needle).

Basic models of field evaporation are now more than 50 years old. The models are extremely simple and ion trajectories are known to be governed by simple electrostatic relationships. Nevertheless, because since 30 years the complexity of materials analysed with the instrument has gradually increased (from simple metals to heterogeneous materials), these simple ingredients could give rise to various image artefacts. The comprehension of these artefacts and aberrations requires the use of numerical model to improve the fidelity of image reconstruction. This paper will show how the modelling approach could be used to understand the image deformations observed experimentally in complex devices or alloys. The role of temperature will also be discussed.