MOLECULAR AND MIXED COADSORBED LAYERS PRODUCED BY NO ADSORPTION ON (1X1) AND (1X2) RH(110)

XPS, LEED and TPD studies have been carried out to characterize and compare NO adsorption and dissociation on (1 x 1) and (1 x 2) Rh(110) surfaces. The O 1s and N 1s binding energies and intensities were used to determine the chemical state and the concentration of NO, N and O in adsorption layers produced at different temperatures and exposures. TPD, LEED and XPS results obtained for NO dissociative adsorption at 400 K indicate that at low N + O coverages the surface is enriched by N, which accounts for the dominating (n x 1)-N reconstruction at coverages less than 0.2 ML. The fractions of O and N located below the top layer change with coverage and temperature. The changes in the adsorption state and surface structure in mixed N + O layers are described on the basis of the present data.