OSTWALD RIPENING OF VACANCY ISLANDS AT THIOL COVERED AU(111)

The growth kinetics of vacancy islands at a Au(111) surface covered wi th self-assembled thiol monolayers has been investigated by in-situ sc anning tunneling microscopy. The vacancy islands are found to coarsen by Ostwald ripening. The exponent characterizing the power-law time de pendence of the coarsening is found to be n approximate to 1/2 indepen dent of the thiol chain length (CH3(CH2)(x)SH, x = 5, 9, 17). This beh avior is consistent with a model in which the mass transport is limite d by the adsorption/desorption rate of vacancies at the hole edges.