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Author Rezende, Marcos V. dos S. ♦ Santos, Denise J. ♦ Jackson, Robert A. ♦ Valerio, Mário E. G. ♦ Macedo, Zélia S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ ABSORPTION ♦ ABSORPTION SPECTROSCOPY ♦ BISMUTH IONS ♦ CHARGE TRANSPORT ♦ COMPARATIVE EVALUATIONS ♦ DEFECTS ♦ DOPED MATERIALS ♦ ELECTRIC CONDUCTIVITY ♦ FINE STRUCTURE ♦ MANGANESE IONS ♦ MIXTURES ♦ SIMULATION ♦ TITANATES ♦ TITANIUM IONS ♦ X RADIATION ♦ X-RAY SPECTROSCOPY
Abstract This work reports an investigation of the valence and site occupancy of Mn dopants in Bi{sub 12}TiO{sub 20} (BTO: Mn) host using X-ray Absorption (XAS) and atomistic simulation techniques based on energy minimisation. X-ray Absorption Near Edge Structure (XANES) at the Mn K-edges gave typical results for Mn ions with mixed valences of 3+ and 4+. Extended X-ray Absorption Fine Structure (EXAFS) results indicated that Mn ions are probably substituted at Ti sites. Atomistic simulation was performed assuming the incorporation of Mn{sup 2+}, Mn{sup 3+} and Mn{sup 4+} ions at either Bi{sup 3+} or Ti{sup 4+} sites, and the results were compared to XANES and EXAFS measurements. Electrical conductivity for pure and doped samples was used to evaluate the consistency of the proposed model. - Graphical abstract: The structure of Bi{sub 12}TiO{sub 20} (BTO). Display Omitted - Highlights: • Pure and Mn-doped Bi{sub 12}TiO{sub 20} samples were studied by experimental techniques combined with atomistic simulation. • Good agreement between experimental and simulation results was obtained. • XANES results suggest a mixture of 3+ and 4+ valences for Mn, occupying the Ti4+ site in both cases. • Charge compensation by holes is most energetically favoured, explaining the enhancement observed in AC dark conductivity.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-06-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 238


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