Monte Carlo simulation of the chemisorption kinetics and initial oxide formation on Al(111)

Monte Carlo (MC) simulations, based on the lattice-gas approach, of the cov erage-dependent chemisorption kinetics and initial oxide formation on Al(11 1) are presented. Three different adsorption mechanisms for the early chemi sorption phase, discussed in the literature, are considered: (i) "hot" dime r dissociation; (ii) abstractive dissociation; and (iii) "normal" dissociat ion without "hot" fragments. The simulation results are compared with the e xperimental scanning tunnel microscope (STM) results by Brune [J. Chem Phys . 99, 2128 (1993)]. The best agreement between the MC simulations and the S TM results is obtained with the hot dimer mechanism. (C) 2000 American Inst itute of Physics. [S0021-9606(00)71044-0].