Phase separation and charge localization in UHV-lithiated anatase TiO{sub 2} nanoparticles

Journal Article · Wed Jun 15 04:00:00 EDT 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.71.235419· OSTI ID:20719064

Richter, J H; Henningsson, A; Sanyal, B; Karlsson, P G; Siegbahn, H; Eriksson, O; Sandell, A ^[1]; Andersson, M P; Uvdal, P ^[2]

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1. Department of Physics, Uppsala University, P.O. Box 530, S-751 21 Uppsala (Sweden)
2. Chemical Physics, Department of Chemistry, Lund University, P.O. Box 124, S-221 00 Lund (Sweden)

The insertion of lithium in anatase TiO{sub 2} nanoparticles under ultrahigh vacuum (UHV) conditions is studied using x-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES) at the Ti L{sub 2,3} edge. It is demonstrated that XAS can be used to monitor the separation into an anatase phase and a lithium titanate phase of formal stoichiometry Li{sub 0.5}TiO{sub 2}. The initial state properties of the Ti 3d states of the lithium titanate phase are investigated using ab initio electronic structure calculations. The calculations show a correlation driven separation of Ti 3d states from the conduction band in agreement with previous studies. It is shown that Ti in different oxidation states (Ti{sup 3+} and Ti{sup 4+}) is formed as a direct consequence of the electron-electron interaction. RPES and XAS spectra confirm the presence of electronically inequivalent Ti sites. The site-sensitivity of the RPES spectra at selected electron binding energies is found to be consistent with the calculations.

• OSTI ID: 20719064
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 23 Vol. 71; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
BINDING ENERGY
CORRELATIONS
ELECTRON-ELECTRON COLLISIONS
ELECTRON-ELECTRON COUPLING
ELECTRON-ELECTRON INTERACTIONS
ELECTRONIC STRUCTURE
ELECTRONS
LITHIUM TITANATES
NANOSTRUCTURES
OXIDATION
PHOTOELECTRON SPECTROSCOPY
SENSITIVITY
STOICHIOMETRY
TITANIUM IONS
TITANIUM OXIDES
VALENCE
X-RAY SPECTRA
X-RAY SPECTROSCOPY