| Abstract
| - We have investigated the formation of Au clusters in a C60 fullerene matrix (binary cluster material) with theaim to produce densely packed arrays of ultrasmall Au clusters with sizes below 4 nm. We achieved theformation of a binary cluster material by co-deposition of Au and C60, and no segregation of the gold wasobserved. The Au concentration throughout the film was observed with Rutherford backscattering spectroscopyand reflects the deposition rates measured for the single particle fluxes. It was determined by high-resolutionTEM that the films show a narrow size distribution of the Au clusters. The size ranges from 1.6 to about 3.8nm, and the size distribution is determined by the Au concentration. For low Au concentrations of less than5 atom %, the maximum of the size distribution was positioned at about 2 nm with a full width at half-maximum of 0.5 nm. The gold appears to have a strong influence on the growth mechanism of the films, asevidenced by a dramatic reduction in the mean roughness of the films with increasing Au content, which wasobserved with atomic force microscopy. For high gold concentrations, the surface roughness decreases toless than half the radius of a C60 molecule. The competition between surface and volume cluster growth andthe role of the Au cluster−fullerene interaction in the film growth are discussed.
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