L. Padillacampos et A. Torolabbe, MONTE-CARLO SIMULATIONS OF THE ADSORPTION OF POTASSIUM ON A CU(111) SURFACE, The Journal of chemical physics, 108(15), 1998, pp. 6458-6465
Monte Carlo simulations of the adsorption of potassium on a Cu(111) su
rface at 80 K and coverages going from theta=0.13 ' to theta=0.26 mono
layer are reported. The particles interact through an adsorbate-substr
ate potential previously derived and through a classical adsorbate-ads
orbate Morse-type potential. Interesting results concerning the nature
of the adsorbed phase have been obtained: (a) We have found that the
potassium adlayer is incommensurate under 1 ML coverage (theta=0.25),
but it becomes commensurate at 1 ML, forming a p(2X2) adlayer with res
pect to the Cu substrate. (b) A procedure to determine the distributio
n of potassium on different adsorption sites in terms of theta has bee
n developed with the result that top sites are the preferred sites for
adsorption, although at low and medium coverages other sites are also
occupied. At 1 ML only the top sites are occupied, in good agreement
with the available experimental data. (C) 1998 American Institute of P
hysics. [S0021-9606(98)00712-0].