Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 17: Poster Session

MM 17.31: Poster

Montag, 26. März 2012, 17:00–19:00, Poster B

Atom probe specimen preparation from nanoporous materials — •Björn Pfeiffer, Torben Erichsen, Eike Epler, and Carsten Nowak — Georg-August-Universität Göttingen, Institut für Materialphysik

During the last years open-celled nanoporous foams attracted a lot of attention because of their physical properties and possible technical applications. For example, with their large surface to volume ratio they are ideal for application as catalysts and as electrodes in batteries. To determine the chemical composition of such heterogeneous materials in three dimensions with sub-nanometer resolution atom probe (AP) exactly fits the requirements. However, problems with mechanical stability during analysis and with data reconstruction arise when analyzing non-compact materials. Here, we demonstrate that electron-beam induced CVD is a promising approach to overcome these problems.

For the experiments, nanoporous gold (np-Au) was used as a model system for nanoporous materials. Electron beam induced CVD of organometallic precursors allows to fill the pores of the material in volumes large enough for AP sample preparation with residual voids in the low nanometer range. Fieldevaporation series in FIM with intermediate TEM-imaging reveal that controlled fieldevaporation of both, np-Au and the deposited precursor is possible and that samples are mechanically stable under electric fields necessary for FIM-imaging. The presented results give an outlook on the opportunities given by this method to analyze open-celled nanoporous materials with FIM and AP.