title: Multicomponent signal unmixing from nanoheterostructures: overcoming the traditional challenges of nanoscale X-ray analysis via machine learning.
abstract: The chemical composition of core-shell nanoparticle clusters have been determined through principal component analysis (PCA) and independent component analysis (ICA) of an energy-dispersive X-ray (EDX) spectrum image (SI) acquired in a scanning transmission electron microscope (STEM). The method blindly decomposes the SI into three components, which are found to accurately represent the isolated and unmixed X-ray signals originating from the supporting carbon film, the shell, and the bimetallic core. The composition of the latter is verified by and is in excellent agreement with the separate quantification of bare bimetallic seed nanoparticles.
authors.affiliation: †Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Rossouw
authors.affiliation: †Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
authors.forename: Pierre
authors.initials: P
authors.lastname: Burdet
authors.affiliation: †Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
authors.forename: Francisco
authors.initials: F
authors.lastname: de la Peña
authors.affiliation: †Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
authors.forename: Caterina
authors.initials: C
authors.lastname: Ducati
authors.affiliation: ‡Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Knappett
authors.affiliation: ‡Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Andrew E H
authors.initials: AE
authors.lastname: Wheatley
authors.affiliation: †Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Midgley
mesh_terms: D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D000069550:Machine Learning; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008422:Materials Testing / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D058185:Magnetite Nanoparticles
keywords: EDX; ICA; TEM; electron microscopy; nanoparticle