Structural and electronic properties of molecularly adsorbed CS 2 on Cu(111) studied by X-ray absorption and photoelectron spectroscopies

Abstract

The surface structure and the electronic properties of submonolayer carbon disulphide CS 2 molecularly adsorbed on Cu(111) at 92 K were investigated by means of S K-edge surface extended X-ray absorption fine structure (SEXAFS), near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) measurements. The CS 2 molecule is found by NEXAFS to lie nearly flat and linearly on the surface with a tilt angle of the molecular axis of 8 ± 5°. NEXAFS and XPS suggest that the adsorbed species is in a state close to CS 2− 2. SEXAFS has clarified the adsorption geometry of the CS 2 molecule, where one S atom locates at the three-fold hollow site and the other S is at the bridge site with a slightly longer S-Cu distance. The determined surface structure is discussed comparing to other molecular adsorbate systems.