| AVS 57th International Symposium & Exhibition | |
| Graphene Focus Topic | Thursday Sessions |
| Session GR+AS+TF-ThM |
| Session: | Graphene Synthesis on Metals |
| Presenter: | A.K. Engstfeld, Ulm University, Germany |
| Authors: | A.K. Engstfeld, Ulm University, Germany S. Beckord, Ulm University, Germany H.E. Hoster, Ulm University, Germany R.J. Behm, Ulm University, Germany |
| Correspondent: | Click to Email |
The Moiré-type nm-scale patterns of graphene monolayers on metal single crystals were recently shown to allow facile fabrication of ordered arrays of virtually monodisperse metal nanoclusters by simple metal vapour deposition in UHV [1-3]. In view of a potential utilization as model systems in electrocatalysis, we have tested the possibility of preparing Ru and bimetallic PtRu clusters by an analogous procedure. This included an extended study on the growth behaviour of the pure Ru clusters. Statistically evaluated STM images indicate that density and height distribution of Ru clusters are largely independent from the evaporation rate at room temperature. Lower/higher cluster densities along with larger/smaller cluster sizes were only achieved by higher/lower substrate temperatures during evaporation. For a given temperature, the lateral density of Ru clusters his higher than that of Pt clusters. Hence, the fabrication of bimetallic clusters can be performed more reliably when Ru is deposited first. We discuss in how far the found growth behaviour can be understood using classic nucleation theory.