What atomic resolution annular dark field imaging can tell us about gold nanoparticles on TiO(2) (110).

Institute of Engineering Innovation, The University of Tokyo, Tokyo 116-0013, Japan.
Ultramicroscopy (Impact Factor: 2.75). 08/2009; 109(12):1435-46. DOI: 10.1016/j.ultramic.2009.07.006
Source: PubMed

ABSTRACT Annular dark field scanning transmission electron microscopy imaging was recently applied to a catalyst consisting of gold nanoparticles on TiO(2) (110), showing directly that the gold atoms in small nanoparticles preferentially attach to specific sites on the TiO(2) (110) surface. Here, through simulation, a parameter exploration of the imaging conditions which maximise the visibility of such nanoparticles is presented. Aberration correction, finite source size and profile imaging are all considered while trying to extracting the maximum amount of information from a given sample. Comment is made on the role of the thermal vibration of the atoms in the nanoparticle, the magnitude of which is generally not known a priori but which affects the visibility of the nanoparticles in this imaging mode.

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