skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: LEED-IV study of the rutile TiO{sub 2}(110)-1x2 surface with a Ti-interstitial added-row reconstruction

Abstract

Upon sputtering and annealing in UHV at {approx}1000 K, the rutile TiO{sub 2}(110) surface undergoes a 1x1{yields}1x2 phase transition. The resulting 1x2 surface is Ti rich, formed by strands of double Ti rows as seen on scanning tunneling microscopic images, but its detailed structure and composition have been subject to debate in the literature for years. Recently, Park et al. [Phys. Rev. Lett. 96, 226105 (2006)] have proposed a model where Ti atoms are located on interstitial sites with Ti{sub 2}O stoichiometry. This model, when it is analyzed using LEED-IV data [Phys. Rev. Lett. 96, 0055502 (2006)], does not yield an agreement between theory and experiment as good as the previous best fit for Onishi and Iwasawa's model for the long-range 1x2 reconstruction. Therefore, the Ti{sub 2}O{sub 3} added row is the preferred one from the point of view low-energy electron diffraction.

Authors:
; ; ; ; ;  [1];  [2];  [3]
  1. Instituto de Ciencia de Materiales (CSIC), Cantoblanco, 28049 Madrid (Spain)
  2. Centro de Investigacion en Optica y Nanofisica, Universidad de Murcia, Campus Espinardo, 30100 Murcia (Spain)
  3. Centro de Astrobiologia (CSIC-INTA), Carretera de Ajalvir km. 4, 28850 Torrejon de Ardoz, Madrid (Spain)
Publication Date:
OSTI Identifier:
20976707
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevB.75.081402; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; ATOMS; ELECTRON DIFFRACTION; IMAGES; INTERSTITIALS; PHASE TRANSFORMATIONS; RUTILE; SCANNING TUNNELING MICROSCOPY; SPUTTERING; SURFACES; TITANIUM OXIDES; TUNNEL EFFECT

Citation Formats

Blanco-Rey, M., Mendez, J., Lopez, M. F., Roman, E., Martin-Gago, J. A., Andres, P. L. de, Abad, J., and Rogero, C. LEED-IV study of the rutile TiO{sub 2}(110)-1x2 surface with a Ti-interstitial added-row reconstruction. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.081402.
Blanco-Rey, M., Mendez, J., Lopez, M. F., Roman, E., Martin-Gago, J. A., Andres, P. L. de, Abad, J., & Rogero, C. LEED-IV study of the rutile TiO{sub 2}(110)-1x2 surface with a Ti-interstitial added-row reconstruction. United States. doi:10.1103/PHYSREVB.75.081402.
Blanco-Rey, M., Mendez, J., Lopez, M. F., Roman, E., Martin-Gago, J. A., Andres, P. L. de, Abad, J., and Rogero, C. Thu . "LEED-IV study of the rutile TiO{sub 2}(110)-1x2 surface with a Ti-interstitial added-row reconstruction". United States. doi:10.1103/PHYSREVB.75.081402.
@article{osti_20976707,
title = {LEED-IV study of the rutile TiO{sub 2}(110)-1x2 surface with a Ti-interstitial added-row reconstruction},
author = {Blanco-Rey, M. and Mendez, J. and Lopez, M. F. and Roman, E. and Martin-Gago, J. A. and Andres, P. L. de and Abad, J. and Rogero, C.},
abstractNote = {Upon sputtering and annealing in UHV at {approx}1000 K, the rutile TiO{sub 2}(110) surface undergoes a 1x1{yields}1x2 phase transition. The resulting 1x2 surface is Ti rich, formed by strands of double Ti rows as seen on scanning tunneling microscopic images, but its detailed structure and composition have been subject to debate in the literature for years. Recently, Park et al. [Phys. Rev. Lett. 96, 226105 (2006)] have proposed a model where Ti atoms are located on interstitial sites with Ti{sub 2}O stoichiometry. This model, when it is analyzed using LEED-IV data [Phys. Rev. Lett. 96, 0055502 (2006)], does not yield an agreement between theory and experiment as good as the previous best fit for Onishi and Iwasawa's model for the long-range 1x2 reconstruction. Therefore, the Ti{sub 2}O{sub 3} added row is the preferred one from the point of view low-energy electron diffraction.},
doi = {10.1103/PHYSREVB.75.081402},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 8,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • Combining STM, LEED, and density functional theory, we determine the atomic surface structure of rutile TiO{sub 2} (110)-(1x2): nonstoichiometric Ti{sub 2}O{sub 3} stripes along the [001] direction. LEED patterns are sharp and free of streaks, while STM images show monatomic steps, wide terraces, and no cross-links. At room temperature, atoms in the Ti{sub 2}O{sub 3} group have large amplitudes of vibration. The long quasi-1D chains display metallic character, show no interaction between them, and cannot couple to bulk or surface states in the gap region, forming good atomic wires.
  • Detailed description is presented of molten salt synthesis, single crystal structures, and a comparison is offered of the {alpha}- and {beta}-La{sub 4}Ti{sub 9}Si{sub 4}O{sub 30} phases. The electrical property and band struture of this mixed-valence titanium (III/IV) oxosilicate series, La{sub 4}Ti(Si{sub 2}O{sub 7}){sub 2}(TiO{sub 2}){sub 4m} (m = 1,2), are discussed in terms of electronic interactions in a confined space with respect to the (110) rutile sheets. The results from the extended Hueckel tight binding calculations and the bond valence sum analysis are contrasted with regard to charge distribution. 33 refs., 9 figs., 3 tabs.
  • Charge transfer between metal nanoparticles and the supported TiO{sub 2} surface is primarily important for catalytic applications as it greatly affects the catalytic activity and the thermal stability of the deposited nanoparticles on the surface. Herein, systematic spin-polarized density functional and HSE06 calculations are performed to evaluate the adsorption, diffusion, and charge state of several transition metal monomers on both stoichiometric and reduced rutile TiO{sub 2} (110) surface. Although the presence of oxygen vacancy (O{sub v}) increases the binding of Au, Pt and Pd on the surface, it weakens the interaction thus enhancing the diffusion for Fe, Co, Ni, Ag,more » and Cu adatoms on the surface. For pristine reduced surface, only a small portion (around 5%) of the excess electrons occupy the topmost surface, which are mainly delocalized at the second nearest and third nearest fivefold coordinated Ti (Ti{sub 5c}) atoms. Excess electrons populating at the Ti{sub 5c} atoms on the basal plane can be transferred to strongly electronegative adsorbates like Au and Pt thus enabling a moderate adsorption at this site, whereas no stable adsorption is found for other less electronegative transition metal adatoms (Ag, Cu, Fe, Co, Ni, and Pd) on the reduced surface and for all the adatoms on stoichiometric surface. This result clarifies the origin of the experimental observation of the adsorption of O{sub 2} and CO molecules at Ti{sub 5c} sites in connection with charge transfer. In addition, the spatial redistribution of the excess electrons around the O{sub v} upon the adsorption of the monomers is thoroughly examined. Our finding of an accumulation of excess electrons at the Ti{sub 5c} sites around the monomers explains the critical role of the perimeter interface of the deposited nanoparticles in promoting the adsorption and activation of reactants observed in experiments.« less
  • Cited by 4
  • Cited by 1