The structure of sodium intercalated 1T and 2H polytypes of TaS2: a photoemission and SEXAFS study

• Published in: Surface science Vol. 331-333; pp. 501 - 505
• Main Authors: Aminpirooz, S., Becker, L., Rossner, H., Schellenberger, A., Holub-Krappe, E.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01.07.1995; Amsterdam Elsevier Science; New York, NY
• Subjects: Compound formation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Crystal binding; cohesive energy; Crystalline state (including molecular motions in solids); Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Extended X-ray absorption fine structure (EXAFS); Low index single crystal surfaces; Photoemission and photoelectron spectra; Physics; Soft X-ray photoelectron spectroscopy; Structure of solids and liquids; crystallography; Sulphides; Tantalum; TaS2; X-ray absorption spectroscopy: exafs, nexafs, xanes, etc; X-ray diffraction and scattering; Extended X-ray absorption fine structure (EXAFS); Tantalum; Compound formation; Low index single crystal surfaces; TaS2; Soft X-ray photoelectron spectroscopy; Sulphides; Inorganic compounds; Adsorption; Polytypism; Sodium; Transition element compounds; Intercalation compounds; Experimental study; Tantalum sulfides; Photoelectron spectroscopy; EXAFS; Bond lengths
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(95)00066-6

Na deposited 1T and 2H polytypes of TaS2 have been investigated by means of surface extended X-ray absorption fine-structure (SEXAFS) and photoemission studies. The photoemission spectra show that at room temperature Na mainly intercalates for both polytypes with no reactive component. The intercalated sodium atoms are positioned in the van der Waals gap in a sixfold coordinated site due to the SEXAFS analysis. The Na-S nearest neighbour distances are 2.95 ± 0.05 Å for 1T and 2.85 ± 0.05 Å for 2H polytype corresponding to an increase of the gap width by 1.5 ± 0.06 and 1.3 ± 0.06 Å, respectively. With increasing amount of deposited Na, a fraction of sodium atoms remains on the surface. The adsorbed Na atoms occupy a threefold hollow site on the surface with a Na-S bond length of 2.91 ± 0.05 Å for 1T and 2.80 ± 0.05 Å for 2H polytype.