Publication Date:
2018-04-15
Description:
Publication date: Available online 13 April 2018 Source: Ultramicroscopy Author(s): Se-Ho Kim, Phil Woong Kang, O Ok Park, Jae-Bok Seol, Jae-Pyoung Ahn, Ji Yeong Lee, Pyuck-Pa Choi We present a new method of preparing needle-shaped specimens for atom probe tomography from freestanding Pd and C-supported Pt nanoparticles. The method consists of two steps, namely electrophoresis of nanoparticles on a flat Cu substrate followed by electrodeposition of a Ni film acting as an embedding matrix for the nanoparticles. Atom probe specimen preparation can be subsequently carried out by means of focused-ion-beam milling. Using this approach, we have been able to perform correlative atom probe tomography and transmission electron microscopy analyses on both nanoparticle systems. Reliable mass spectra and three-dimensional atom maps could be obtained for Pd nanoparticle specimens. In contrast, atom probe samples prepared from C-supported Pt nanoparticles showed uneven field evaporation and hence artifacts in the reconstructed atom maps. Our developed method is a viable means of mapping the three-dimensional atomic distribution within nanoparticles and is expected to contribute to an improved understanding of the structure-composition-property relationships of various nanoparticle systems.
Print ISSN:
0304-3991
Topics:
Electrical Engineering, Measurement and Control Technology
,
Natural Sciences in General
,
Physics
