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Title: Atomistic simulation and XAS investigation of Mn induced defects in Bi{sub 12}TiO{sub 20}

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 ACmore » dark conductivity.« less

Authors:
 [1];  [2];  [3]; ;  [2]
  1. Functional Nanomaterials Group, Physics Department, Federal University of Sergipe, Campus Universitário Professor Alberto Carvalho, 49500-000 Itabaiana-SE (Brazil)
  2. Physics Department, Federal University of Sergipe, São Cristovão, 49000-000 SE (Brazil)
  3. School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom)
Publication Date:
OSTI Identifier:
22584121
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 238; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 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

Citation Formats

Rezende, Marcos V dos S., Santos, Denise J., Jackson, Robert A., Valerio, Mário E.G., and Macedo, Zélia S.. Atomistic simulation and XAS investigation of Mn induced defects in Bi{sub 12}TiO{sub 20}. United States: N. p., 2016. Web. doi:10.1016/J.JSSC.2016.03.029.
Rezende, Marcos V dos S., Santos, Denise J., Jackson, Robert A., Valerio, Mário E.G., & Macedo, Zélia S.. Atomistic simulation and XAS investigation of Mn induced defects in Bi{sub 12}TiO{sub 20}. United States. doi:10.1016/J.JSSC.2016.03.029.
Rezende, Marcos V dos S., Santos, Denise J., Jackson, Robert A., Valerio, Mário E.G., and Macedo, Zélia S.. Wed . "Atomistic simulation and XAS investigation of Mn induced defects in Bi{sub 12}TiO{sub 20}". United States. doi:10.1016/J.JSSC.2016.03.029.
@article{osti_22584121,
title = {Atomistic simulation and XAS investigation of Mn induced defects in Bi{sub 12}TiO{sub 20}},
author = {Rezende, Marcos V dos S. and Santos, Denise J. and Jackson, Robert A. and Valerio, Mário E.G. and Macedo, Zélia S.},
abstractNote = {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.},
doi = {10.1016/J.JSSC.2016.03.029},
journal = {Journal of Solid State Chemistry},
number = ,
volume = 238,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2016},
month = {Wed Jun 15 00:00:00 EDT 2016}
}