Aggregated nanoparticles: Sample preparation and analysis by atom probe tomography

Cédric Barroo; Austin J Akey; David C Bell

doi:10.1016/j.ultramic.2020.113082

Aggregated nanoparticles: Sample preparation and analysis by atom probe tomography

Ultramicroscopy. 2020 Nov:218:113082. doi: 10.1016/j.ultramic.2020.113082. Epub 2020 Jul 22.

Authors

Cédric Barroo¹, Austin J Akey², David C Bell³

Affiliations

¹ Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge MA 02138, USA; Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge MA 02138, USA. Electronic address: cbarroo@ulb.ac.be.
² Center for Nanoscale Systems, Harvard University, 11 Oxford Street, Cambridge MA 02138, USA.
³ Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge MA 02138, USA; Center for Nanoscale Systems, Harvard University, 11 Oxford Street, Cambridge MA 02138, USA. Electronic address: dcb@seas.harvard.edu.

PMID: 32731130
DOI: 10.1016/j.ultramic.2020.113082

Abstract

Atom probe tomography (APT) allows measurement of the three-dimensional structure and composition of materials, but specific sample preparation procedures are required for challenging materials such as aggregates of nanoparticles. Indeed, the presence of porosity within the specimen affects both the stability of the sample and the accuracy of the data. Here, aggregates of nanoparticles were transferred onto a micromanipulator tip and embedded via electron-beam-assisted deposition of Pt. Successive FIB-millings and Pt-depositions are needed to create suitable APT tips. The 3D reconstruction reveals the presence of 15-20 nm nanoparticles, and mass-spectral analysis shows the absence of trace elements within the catalyst, thus serving as quality control for the synthesis of nanoparticles with specific compositions.

Keywords: APT; Aggregated nanoparticles; Atom probe tomography; Cu catalyst; FIB sample preparation.