The adsorption of benzene on the Pt(111) surface studied by low-energy electron diffraction intensity measurements and quantitative Auger electron spectroscopy

Abstract

Benzene, when chemisorbed on the Pt(111) crystal face forms an ordered metastable ‖⁴_{0 4}⁻²‖ surface structure which transforms, slowly, to a stable ‖⁴_{0 5}⁻²‖ surface structure. A complete set of intensity–voltage (I vs V) curves are presented in the appendix to aid in solving the surface structures of this complex organic molecule. The size of the unit cells and the larger than monolayer carbon surface concentrations (determined by quantitative Auger spectroscopy) indicate that most of the adsorbed benzene molecules are inclined at an angle to the surface. The similarity of the (I–V) profiles for the same diffraction beams from the two structures indicate that the carbon–platinum layer spacing changes very little during the order–order transformation.