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A Rietveld refinement method for angular- and wavelength-dispersive neutron time-of-flight powder diffraction data.

Jacobs, Philipp; Houben, Andreas; Schweika, Werner LU ; Tchougréeff, Andrei L and Dronskowski, Richard (2015) In Journal of Applied Crystallography 48(Pt 6). p.1627-1636
Abstract
This paper introduces a two-dimensional extension of the well established Rietveld refinement method for modeling neutron time-of-flight powder diffraction data. The novel approach takes into account the variation of two parameters, diffraction angle 2θ and wavelength λ, to optimally adapt to the varying resolution function in diffraction experiments. By doing so, the refinement against angular- and wavelength-dispersive data gets rid of common data-reduction steps and also avoids the loss of high-resolution information typically introduced by integration. In a case study using a numerically simulated diffraction pattern of Rh0.81Fe3.19N taking into account the layout of the future POWTEX instrument, the profile function as parameterized... (More)
This paper introduces a two-dimensional extension of the well established Rietveld refinement method for modeling neutron time-of-flight powder diffraction data. The novel approach takes into account the variation of two parameters, diffraction angle 2θ and wavelength λ, to optimally adapt to the varying resolution function in diffraction experiments. By doing so, the refinement against angular- and wavelength-dispersive data gets rid of common data-reduction steps and also avoids the loss of high-resolution information typically introduced by integration. In a case study using a numerically simulated diffraction pattern of Rh0.81Fe3.19N taking into account the layout of the future POWTEX instrument, the profile function as parameterized in 2θ and λ is extracted. As a proof-of-concept, the resulting instrument parameterization is then utilized to perform a typical refinement of the angular- and wavelength-dispersive diffraction pattern of CuNCN, yielding excellent residuals within feasible computational efforts. Another proof-of-concept is carried out by applying the same approach to a real neutron diffraction data set of CuNCN obtained from the POWGEN instrument at the Spallation Neutron Source in Oak Ridge. The paper highlights the general importance of the novel approach for data analysis at neutron time-of-flight diffractometers and its possible inclusion within existing Rietveld software packages. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Applied Crystallography
volume
48
issue
Pt 6
pages
1627 - 1636
publisher
Wiley-Blackwell
external identifiers
  • pmid:26664340
  • wos:000365774800005
  • scopus:84948753527
ISSN
1600-5767
DOI
10.1107/S1600576715016520
language
English
LU publication?
yes
id
bb58b149-eeca-4815-a550-d4550c8be613 (old id 8504872)
date added to LUP
2016-01-08 08:49:50
date last changed
2017-06-25 03:07:13
@article{bb58b149-eeca-4815-a550-d4550c8be613,
  abstract     = {This paper introduces a two-dimensional extension of the well established Rietveld refinement method for modeling neutron time-of-flight powder diffraction data. The novel approach takes into account the variation of two parameters, diffraction angle 2θ and wavelength λ, to optimally adapt to the varying resolution function in diffraction experiments. By doing so, the refinement against angular- and wavelength-dispersive data gets rid of common data-reduction steps and also avoids the loss of high-resolution information typically introduced by integration. In a case study using a numerically simulated diffraction pattern of Rh0.81Fe3.19N taking into account the layout of the future POWTEX instrument, the profile function as parameterized in 2θ and λ is extracted. As a proof-of-concept, the resulting instrument parameterization is then utilized to perform a typical refinement of the angular- and wavelength-dispersive diffraction pattern of CuNCN, yielding excellent residuals within feasible computational efforts. Another proof-of-concept is carried out by applying the same approach to a real neutron diffraction data set of CuNCN obtained from the POWGEN instrument at the Spallation Neutron Source in Oak Ridge. The paper highlights the general importance of the novel approach for data analysis at neutron time-of-flight diffractometers and its possible inclusion within existing Rietveld software packages.},
  author       = {Jacobs, Philipp and Houben, Andreas and Schweika, Werner and Tchougréeff, Andrei L and Dronskowski, Richard},
  issn         = {1600-5767},
  language     = {eng},
  number       = {Pt 6},
  pages        = {1627--1636},
  publisher    = {Wiley-Blackwell},
  series       = {Journal of Applied Crystallography},
  title        = {A Rietveld refinement method for angular- and wavelength-dispersive neutron time-of-flight powder diffraction data.},
  url          = {http://dx.doi.org/10.1107/S1600576715016520},
  volume       = {48},
  year         = {2015},
}