Phase separation and charge localization in UHV-lithiated anatase TiO2 nanoparticles
2005 (English)In: Physical Review B, ISSN 1098-0121, Vol. 71, no 23, 235419- p.Article in journal (Refereed) Published
The insertion of lithium in anatase TiO2 nanoparticles under ultrahigh vacuum (UHV) conditions is studied using x-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES) at the Ti L2,3 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 Li0.5TiO2. 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 (Ti3+ and Ti4+) 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.
Place, publisher, year, edition, pages
2005. Vol. 71, no 23, 235419- p.
X-RAY-ABSORPTION, TRANSITION-METAL COMPOUNDS, LITHIUM INTERCALATION, PHOTOELECTRON-SPECTROSCOPY, ELECTRONIC-STRUCTURE, ION INSERTION, 2P, LI0.5TIO2, BATTERIES, SPECTRA
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-77449DOI: doi:10.1103/PhysRevB.71.235419OAI: oai:DiVA.org:uu-77449DiVA: diva2:105361