Characterising the surface and interior chemistry of core-shell nanoparticles using scanning transmission electron microscopy

Mendis, B.G. and Craven, A. (2011) Characterising the surface and interior chemistry of core-shell nanoparticles using scanning transmission electron microscopy. Ultramicroscopy, 111(3), pp. 212-226. (doi: 10.1016/j.ultramic.2010.11.002)

Abstract

A method for extracting core and shell spectra from core–shell particles with varying core to shell volume fractions is described. The method extracts the information from a single EELS spectrum image of the particle. The distribution of O and N was correctly reproduced for a nanoparticle with a TiN core and Ti-oxide shell. In addition, the O distribution from a nanoparticle with a Cu core and a Cu-oxide shell was obtained, and the extracted Cu L_2,3-core and shell spectra showed the required change in EELS near edge fine structure. The extracted spectra can be used for multiple linear least squares fitting to the raw data in the spectrum image. The effect of certain approximations on numerical accuracy, such as treating the nanoparticle as a perfect sphere, as well as the intrinsic detection limits of the technique have also been explored. The technique is most suitable for qualitative, rather than quantitative, work.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mendis, Dr Budhika and Craven, Professor Alan
• Authors: Mendis, B.G., and Craven, A.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Ultramicroscopy
• Publisher: Elsevier
• ISSN: 0304-3991
• ISSN (Online): 1879-2723
• Published Online: 11 November 2010
• Copyright Holders: Copyright © 2010 Elsevier B.V.
• First Published: First published in Ultramicroscopy 111 (3) : 212-226
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
41337	1	SuperSTEM - the UK aberration corrected STEM facility	Alan Craven	Engineering & Physical Sciences Research Council (EPSRC)	EP/D040205/1	Physics and Astronomy