Author/Authors :
Hofmann، نويسنده , , Jan Philipp and Rohrlack، نويسنده , , Stefan F. and Heك، نويسنده , , Franziska and Goritzka، نويسنده , , Jan C. and Krause، نويسنده , , Philipp P.T. and Seitsonen، نويسنده , , Ari P. and Moritz، نويسنده , , Wolfgang and Over، نويسنده , , Herbert، نويسنده ,
Abstract :
Chlorine adsorption on Ru(0001) surface has been studied by a combined density functional theory (DFT) and quantitative low energy electron diffraction (LEED) approach. The (√3 × √3)R30°-Cl phase with ΘCl = 1/3 ML and chlorine sitting in fcc sites has been identified by DFT calculations as the most stable chlorine adsorbate structure on Ru(0001) with an adsorption energy of − 220 kJ/mol. The atomic geometry of (√3 × √3)R30°-Cl was determined by quantitative LEED. The achieved agreement between experimental and simulated LEED data is quantified by a Pendry factor of rP = 0.19 for a fcc adsorption site with a Cl-Ru bond length of 2.52 Å. At chlorine coverages beyond 1/3 ML LEED reveals diffuse diffraction rings, indicating a continuous compression of the hexagonal Cl overlayer with a preferred average Cl–Cl distance of 4.7 Å in the (√3 × √3)R30°-Cl, ΘCl = 1/3 ML phase towards 3.9 Å at saturation coverage of 0.48 ML.
Keywords :
Low energy electron diffraction (LEED) , Density functional theory , Adsorption , Ruthenium , Chlorine , surface structure
