title: Point-by-point compositional analysis for atom probe tomography.
abstract: This new alternate approach to data processing for analyses that traditionally employed grid-based counting methods is necessary because it removes a user-imposed coordinate system that not only limits an analysis but also may introduce errors. We have modified the widely used "binomial" analysis for APT data by replacing grid-based counting with coordinate-independent nearest neighbour identification, improving the measurements and the statistics obtained, allowing quantitative analysis of smaller datasets, and datasets from non-dilute solid solutions. It also allows better visualisation of compositional fluctuations in the data. Our modifications include:.•using spherical k-atom blocks identified by each detected atom's first k nearest neighbours.•3D data visualisation of block composition and nearest neighbour anisotropy.•using z-statistics to directly compare experimental and expected composition curves. Similar modifications may be made to other grid-based counting analyses (contingency table, Langer-Bar-on-Miller, sinusoidal model) and could be instrumental in developing novel data visualisation options.
authors.affiliation: Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechatronic and Mechanical Engineering, The University of Sydney, NSW 2006, Australia.
authors.forename: Leigh T
authors.initials: LT
authors.lastname: Stephenson
authors.affiliation: Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechatronic and Mechanical Engineering, The University of Sydney, NSW 2006, Australia.
authors.forename: Anna V
authors.initials: AV
authors.lastname: Ceguerra
authors.affiliation: Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechatronic and Mechanical Engineering, The University of Sydney, NSW 2006, Australia.
authors.forename: Tong
authors.initials: T
authors.lastname: Li
authors.affiliation: Centre for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
authors.forename: Tanaporn
authors.initials: T
authors.lastname: Rojhirunsakool
authors.affiliation: Centre for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
authors.forename: Soumya
authors.initials: S
authors.lastname: Nag
authors.affiliation: Centre for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
authors.forename: Rajarshi
authors.initials: R
authors.lastname: Banerjee
authors.affiliation: Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechatronic and Mechanical Engineering, The University of Sydney, NSW 2006, Australia.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Cairney
authors.affiliation: Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechatronic and Mechanical Engineering, The University of Sydney, NSW 2006, Australia.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Ringer
keywords: Atom probe compositional analysis; Atom probe microscopy; Binomial analysis; Compositional analysis; Nearest neighbours