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Title: Local and average structure of Mn- and La-substituted BiFeO{sub 3}

Abstract

The local and average structure of solid solutions of the multiferroic perovskite BiFeO{sub 3} is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space group symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO{sub 3}. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions. - Graphical abstract:more » The experimental and simulated partial pair distribution functions (PDF) for BiFeO{sub 3}, BiFe{sub 0.875}Mn{sub 0.125}O{sub 3}, BiFe{sub 0.75}Mn{sub 0.25}O{sub 3} and Bi{sub 0.9}La{sub 0.1}FeO{sub 3}.« less

Authors:
;
Publication Date:
OSTI Identifier:
22658290
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 250; Other Information: Copyright (c) 2017 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; BISMUTH COMPOUNDS; COMPUTER CALCULATIONS; DENSITY FUNCTIONAL METHOD; DISTRIBUTION FUNCTIONS; ELECTRON DENSITY; EXPERIMENTAL DATA; FERRITES; FERROELECTRIC MATERIALS; MANGANESE COMPOUNDS; OXIDES; SIMULATION; SOLID SOLUTIONS; SPACE GROUPS; STRUCTURAL MODELS; X-RAY DIFFRACTION

Citation Formats

Jiang, Bo, and Selbach, Sverre M., E-mail: selbach@ntnu.no. Local and average structure of Mn- and La-substituted BiFeO{sub 3}. United States: N. p., 2017. Web. doi:10.1016/J.JSSC.2017.03.021.
Jiang, Bo, & Selbach, Sverre M., E-mail: selbach@ntnu.no. Local and average structure of Mn- and La-substituted BiFeO{sub 3}. United States. doi:10.1016/J.JSSC.2017.03.021.
Jiang, Bo, and Selbach, Sverre M., E-mail: selbach@ntnu.no. Thu . "Local and average structure of Mn- and La-substituted BiFeO{sub 3}". United States. doi:10.1016/J.JSSC.2017.03.021.
@article{osti_22658290,
title = {Local and average structure of Mn- and La-substituted BiFeO{sub 3}},
author = {Jiang, Bo and Selbach, Sverre M., E-mail: selbach@ntnu.no},
abstractNote = {The local and average structure of solid solutions of the multiferroic perovskite BiFeO{sub 3} is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space group symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO{sub 3}. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions. - Graphical abstract: The experimental and simulated partial pair distribution functions (PDF) for BiFeO{sub 3}, BiFe{sub 0.875}Mn{sub 0.125}O{sub 3}, BiFe{sub 0.75}Mn{sub 0.25}O{sub 3} and Bi{sub 0.9}La{sub 0.1}FeO{sub 3}.},
doi = {10.1016/J.JSSC.2017.03.021},
journal = {Journal of Solid State Chemistry},
number = ,
volume = 250,
place = {United States},
year = {Thu Jun 15 00:00:00 EDT 2017},
month = {Thu Jun 15 00:00:00 EDT 2017}
}