Self-consistent atom probe tomography reconstructions utilizing electron microscopy

• Published in: Ultramicroscopy Vol. 195; no. C; pp. 32 - 46
• Main Authors: Diercks, David R., Gorman, Brian P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-12-2018; Elsevier
• Subjects: Atom probe tomography; Detection efficiency; Image compression factor; Reconstruction; Transmission electron microscopy; Reconstruction; Image compression factor; Transmission electron microscopy; Detection efficiency; Atom probe tomography
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/j.ultramic.2018.08.019

•The relationships between atom probe tomography reconstruction parameters are presented.•Atom probe tomography reconstructions where the values known from electron microscopy and the user input values are completely consistent with the output reconstructions are demonstrated.•A consistent power law relationship between the image compression factor and detection efficiency is found for all of the analyzed specimens.•This technique may be used to find the specimen evaporation field at the end of the atom probe analysis and to possibly determine how many atoms were undetected/unranged.•Concepts in this methodology should allow for straightforward incorporation into atom probe tomography reconstruction software.
Atom probe tomography reconstructions provide valuable information on nanometer-scale compositional variations within materials. As such, the spatial accuracy of the reconstructions is of primary importance for the resulting conclusions to be valid. Here, the use of transmission electron microscopy images before and after atom probe analysis to provide additional information and constraints is examined for a number of different materials. In particular, the consistency between the input reconstruction parameters and the output reconstruction is explored. It is demonstrated that it is possible to generate reconstructions in which the input and known values are completely consistent with the output reconstructions. Yet, it is also found that for all of the datasets examined, a particular power law relationship exists such that, if the image compression factor or detection efficiency is not constrained, a series of similarly spatially accurate reconstructions results. However, if one of these values can be independently assessed, then the other is known as well. Means of incorporating these findings and this general methodology into reconstruction protocols are also discussed.