Scaling of size distributions of C60 and C70 fullerene surface islands

Abstract

We present experimental data and a theoretical analysis for the size distributions of C60 and C70 surface islands deposited onto In-modified Si(111)√3×√3-Au surface under different conditions. We show that both fullerene islands feature an analytic Vicsek-Family scaling shape where the scaled size distributions are given by a power law times an incomplete beta-function with the required normalization. The power exponent in this distribution corresponds to the fractal shape of two-dimensional islands, confirmed by the experimentally observed morphologies. Quite interestingly, we do not see any significant difference between C60 and C70 fullerenes in terms of either scaling parameters or temperature dependence of the diffusion constants. In particular, we deduce the activation energy for surface diffusion of ED=140±10meV for both types of fullerenes.