The Library
Data for Structural Disorder in (Bi, M)2(Fe, Mn, Bi)2O6+x (M = Na or K) Pyrochlores Seen from Reverse Monte Carlo Analysis of Neutron Total Scattering
Tools
Walton, Richard I. (2017) Data for Structural Disorder in (Bi, M)2(Fe, Mn, Bi)2O6+x (M = Na or K) Pyrochlores Seen from Reverse Monte Carlo Analysis of Neutron Total Scattering. [Dataset]
Archive (ZIP) (Pair distribution functions for the K-pyrochlore and Na-pyrochlore in two ASCII files)
data.zip - Unspecified Version Available under License Creative Commons Attribution 4.0. Download (10Kb) |
|
Plain Text (README file)
readme_90401.txt - Unspecified Version Available under License Creative Commons Attribution 4.0. Download (325b) |
Official URL: https://wrap.warwick.ac.uk/90401/
Abstract
The average structures of the polycrystalline pyrochlores (Na0.60Bi1.40)(Fe1.06Mn0.17Bi0.77)O6.87 and (K0.24Bi1.51)(Fe1.07Mn0.15Bi0.78)O6.86 can be refined through Rietveld refinement against Bragg scattering data using cubic space group Fd3 ̅m, with off-centred 96h and 32e positions describing the A2Oʹ network. Investigation of their local structures through neutron total scattering confirms the extent of disorder within these materials, and furthermore shows significant deviation from the average structure, which is not accounted for through analysis of Bragg data alone. Reverse Monte Carlo (RMC) analysis with a 6 × 6 × 6 supercell was used to model accurately this local disorder, revealing ellipsoidal distributions for A-site potassium, distinctly different to the hollow torus-shaped distributions for the sodium and bismuth cations. It is shown through bond valence sum analysis that whilst these atomic displacements allow for the steric preferences of Bi3+, they are also necessary to satisfy the valence of both the bismuth and the alkali metals on the A sites. Analysis of the final RMC configuration showed the BO6 octahedra for the separate B site metals to be more regular (O–B–O ≈ 90°) than those in the Rietveld model (O–B–O ≈ 85/95°) which describes an average of the three different environments.
Item Type: | Dataset | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Subjects: | Q Science > QD Chemistry | ||||||||||||||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Chemistry | ||||||||||||||||||
Type of Data: | |||||||||||||||||||
Library of Congress Subject Headings (LCSH): | Chemistry, Physical and theoretical, Monte Carlo method, Niobium | ||||||||||||||||||
Publisher: | University of Warwick, Department of Chemistry | ||||||||||||||||||
Official Date: | 27 July 2017 | ||||||||||||||||||
Dates: |
|
||||||||||||||||||
Status: | Not Peer Reviewed | ||||||||||||||||||
Media of Output (format): | ASCII files | ||||||||||||||||||
Access rights to Published version: | Restricted or Subscription Access | ||||||||||||||||||
Description: | Two ascii files are present that contain the pair distribution functions for the K-pyrochlore and Na-pyrochlore. |
||||||||||||||||||
RIOXX Funder/Project Grant: |
|
||||||||||||||||||
Related URLs: | |||||||||||||||||||
Contributors: |
|
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year