Atom probe tomography of nanoparticles
P. Felfer12, K. Eder12, P. Benndorf3, A. Masters3, T. Maschmayer3, N. Kruse6, S.P.
Ringer12 and J. M. Cairney12
1School for Aerospace, Mechanical and Mechatronic Engineering, The University of
Sydney, NSW 2006, Australia
2Australian Centre for Microscopy and Microanalysis, The University of Sydney,
NSW 2006, Australia
3School of Chemistry, The University of Sydney, NSW 2006, Australia
6Chemical Physics of Materials (Catalysis-Tribology), UL Bruxelles, Brussels,
Belgium
e: peter.felfer@sydney.edu.au
Nanoparticles are used in many applications including catalysis, optical and
magnetical applications and the biological sciences. In the case of core – shell and
other alloy nanoparticles, the 3D distribution of the individual chemical elements is
known to have a profound influence on the properties [1].
A thorough understanding of the properties of compound nanoparticles is therefore
only possible through 3D atomic scale characterisation that is able to resolve
individual elements. We will present methods that are suitable to determine the 3D
chemical structure of nanoparticles by atom probe tomography (APT, [2]). APT is a
single atom mass spectrometry method that allows us to determine the location of
individual atoms at the nm scale or below in 3D by using the principle of sequential
field evaporation. APT is equally sensitive to both light and heavy elements and is
therefore ideally suited for the analysis of nanoparticles if they can be field
evaporated. We have used this method to characterise core shell nanoparticles in the
Co-Cu / Co–Cu–Mn systems [3] and the Ag-Au system [4], by incorporating them into
a solid matrix in order to facilitate controlled field evaporated in the atom probe.
Using this data we are able to show individual surface coverages as well as
structures that exist within the nanoparticles that have previously been
experimentally inaccessible. This is correlated with the properties of the
nanoparticles, especially with respect to catalytic performance.
Acknowledgements: The authors acknowledge the facilities, and the scientific and
technical assistance, of the Australian Microscopy & Microanalysis Research Facility
at the Australian Centre for Microscopy and Microanalysis at the University of
Sydney.
References
[1] R. Ferrando, J. Jellinek and R. Johnston, Nanoalloys: From Theory to
Applications of Alloy Clusters and Nanoparticles, Chem. Rev. 2008 108 (3), 845910
[2] Gault, B., Moody, M.P., Cairney, J.M., Ringer, S.P., Springer Heidelberfg, 2012
[3] Long-Chain Terminal Alcohols through Catalytic CO Hydrogenation, Y. Xiang, V.
Chitry, P. Liddicoat, P. Felfer, J. Cairney, S. Ringer, and N. Kruse, J. Am. Chem.
Soc. 2013 135 (19), 7114-7117
[4] P. Felfer, P. Benndorf, A. Masters, T. Maschmayer and J. Cairney, Angewandte
Chemie Int. Ed., in press.