Interatomic Interaction at the Aluminum–Fullerene C60 Interface

We propose a model of interaction between aluminum and carbon atoms at the Al/C60 interface. The binding energy and the fullerene position of the Al(111) substrate are calculated using the density functional theory. The results are used for determining the parameters of the Lennard-Jones potential, which is then used in investigations based on the molecular dynamics method. Theoretical investigation of the fullerene desorption from the aluminum substrate demonstrates good agreement of the results with available experimental data. Capillary effects emerging at the interface between the aluminum melt and fullerenes embedded in it are studied. The positive value of the specific free energy per unit Al/C60 surface indicates poor wettability of molecules by the melt. The calculated value of the diffusion relaxation time turns out to be two orders of magnitude smaller than the characteristic fullerene coagulation time, indicating the existence of repulsive forces between them. The activation nature of the coagulation process and the capillary origin of the interaction between fullerenes are discussed.