Polarized X-ray absorption spectroscopy and XPS of TiS3: S K- and Ti L-edge XANES and S and Ti 2p XPS

• Published in: Surface science Vol. 584; no. 2-3; pp. 133 - 145
• Main Authors: Fleet, M.E., Harmer, S.L., Liu, X., Nesbitt, H.W.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 20.06.2005; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Layered structures; Physics; Sulfides; TiS3; X-ray absorption near edge spectroscopy; X-ray photoelectron spectroscopy; Sulfides; TiS3; X-ray absorption near edge spectroscopy; X-ray photoelectron spectroscopy; Layered structures; X-ray absorption spectra; XANES; X-ray photoelectron spectra
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2005.03.048

Sulfur and Ti 2p XPS and polarized S K- and L2,3- and Ti L2,3-edge XANES spectra have been obtained from oriented ribbon-like crystals of TiS3 grown by vapor transport. The S 2p XPS spectrum for (001) crystal faces has line widths of 0.53eV and is completely accounted for by partially overlapped 2p3/2/2p1/2 doublets for sulfide (S2−) and disulfide (S22-) species, which are separate and independent entities in TiS3. Evidence of unsaturated surface states is lacking, consistent with a surface monolayer for the (001) growth face of disulfide atoms oriented with their charge-neutral sides outward. The S K-edge XANES spectra show pronounced anisotropy in the (001) plane of TiS3 crystals, associated with the photoelectron transition channel S 1s→3pxσu∗ with the electric vector (E) parallel the a-axis (and the S–S bond of the disulfide group), and transitions to unoccupied antibonding orbitals of S–Ti bonds with E parallel to the b-axis (the direction of the well-known quasi-one-dimensional character of TiS3). The XPS and ultrasoft and soft X-ray region XANES spectra confirm the surface and near-surface structural integrity of TiS3.