Adsorption binding-energy variation resulting from substrate size effects
Results of a computer investigation of the influence of crystallite finite lateral size and thickness upon the binding-energy heterogeneity of typical physisorption substrates are reported. Size effects are shown to contribute large tails to the binding-energy distribution. Calculations with the model substrate (100-Å typical surface coherence length) show that 20%-30% of the binding sites have energies which differ from the average binding energy by greater than 0.2%. Size effects alone, however, are insufficient to explain the distribution peak widths of real substrates.
Physical Review B