[Back]

C. Konvicka, A. Hammerschmid, M. Schmid, P. Varga:
"Stabilizing single metal adatoms at room temperature: Pd on C- and O-covered V(100)";
Surface Science, 496 (2002), 209 - 220.

The initial stages of Pd thin film growth on clean and C- and O-precovered V(100) surfaces at room temperature (RT) and 200°C have been
studied by means of scanning tunneling microscopy (STM) and Auger electron spectroscopy (AES). In the presence of C and O, the adsorption of Pd
atoms in the clean four-fold hollow sites of the V surface is strongly preferred. Upon deposition of Pd in the submonolayer range, it was possible
to stabilize single Pd adatoms and small clusters at RT. Annealing such a surface at 200°C leads to the formation of rectangular Pd islands (size
approx. 40x40 Å₂) and to the compression of the initial C and O adlayer in the areas between the Pd. For higher Pd coverages we found that
oxygen acts as an anti-surfactant, shifting the onset of second layer growth dramatically. The reason for the change of the growth mode of Pd on
V(100) from Stranski-Krastanov to a Volmer-Weber-type growth in the presence of oxygen can be found in a higher free energy of the
film/substrate interface compared to the clean surface.

http://www.iap.tuwien.ac.at/www/SURFACE/abstracts/A2002E02.HTML