Microscopy and Microanalysis

Techniques and Software Development

A New Approach to the Determination of Concentration Profiles in Atom Probe Tomography

Peter J. Felfera1 c1, Baptiste Gaulta1, Gang Shaa1, Leigh Stephensona1, Simon P. Ringera1 and Julie M. Cairneya1

a1 Australian Centre for Microscopy and Microanalysis, Madsen Building F09, The University of Sydney, NSW 2006, Camperdown, Australia

Abstract

Atom probe tomography (APT) provides three-dimensional analytical imaging of materials with near-atomic resolution using pulsed field evaporation. The processes of field evaporation can cause atoms to be placed at positions in the APT reconstruction that can deviate slightly from their original site in the material. Here, we describe and model one such process—that of preferential retention of solute atoms in multicomponent systems. Based on relative field evaporation probabilities, we calculate the point spread function for the solute atom distribution in the “z,” or in-depth direction, and use this to extract more accurate solute concentration profiles.

(Received March 31 2011)

(Accepted September 23 2011)

Correspondence:

c1 Corresponding author. E-mail: peter.felfer@sydney.edu.au