DPG Phi
Verhandlungen
Verhandlungen
DPG

Regensburg 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 82: Fundamentals of Catalysis II

O 82.1: Vortrag

Donnerstag, 4. April 2019, 15:00–15:15, H5

Embedding of cluster superlattices to prevent sintering — •Tobias Hartl, Moritz Will, Pantelis Bampoulis, and Thomas Michely — II. Physikalische Institut, Universität zu Köln

Deposition of a metal, for example Ir, Pt, or W, on the moiré of Gr on Ir(111) leads to a well-ordered cluster superlattice [1]. These clusters are tunable in size, from a few up to hundreds of atoms each, and are of interest for catalysis due to their size dependent properties. However, their use is limited by their low thermal stability against sintering, which for the system under concern takes place by cluster diffusion and coalescence (Smoluchowki ripening) and starts around 500 K. Sintering destroys cluster order, broadens the size distribution and greatly reduces the cluster number density.

Here we explore embedding of an Ir cluster superlattice on Gr/Ir(111) into a matrix of elemental carbon. With increasing deposited amount of carbon, a conformal carbon coverage of the metal clusters establishes. As evidenced by scanning tunnelling microscopy, the embedding process does not affect the order of the cluster superlattice. Most important, sintering of the clusters by Smoluchowski ripening is suppressed up to the highest investigated temperatures of 1350 K.

[1] N'Diaye, AT. et al., New Journal of Physics, 2009

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2019 > Regensburg