The dislocation model of strain anisotropy in whole powder-pattern fitting: The case of an Li-Mn cubic spinel

T. Ungár, M. Leoni, P. Scardi

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Anisotropic strain broadening in X-ray or neutron powder diffraction can cause severe difficulties in whole powder-pattern fitting and Rietveld structure refinement. Several phenomenological models have been proposed to deal with this problem. These, however, lack physically sound bases. In the present work the dislocation-based model of strain anisotropy is applied in the Fourier formalism of profile fitting. It is shown that the anisotropic contrast of dislocations can fully account for strain anisotropy. A few physically sound parameters, namely the average dislocation density, the average coherent domain size, the dislocation arrangement parameter and the dislocation contrast factors, enable a perfect profile fitting to the powder pattern of a cubic Li-Mn spinel obtained at the Daresbury synchrotron storage ring.

Original languageEnglish
Pages (from-to)290-295
Number of pages6
JournalJournal of Applied Crystallography
Volume32
Issue number2
Publication statusPublished - 1999

Fingerprint

Anisotropy
Powders
spinel
Neutron Diffraction
Powder Diffraction
anisotropy
Synchrotrons
Least-Squares Analysis
Acoustic waves
Neutron powder diffraction
Storage rings
X-Rays
X ray powder diffraction
acoustics
profiles
synchrotrons
spinell
formalism
neutrons
causes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Structural Biology

Cite this

The dislocation model of strain anisotropy in whole powder-pattern fitting : The case of an Li-Mn cubic spinel. / Ungár, T.; Leoni, M.; Scardi, P.

In: Journal of Applied Crystallography, Vol. 32, No. 2, 1999, p. 290-295.

Research output: Contribution to journalArticle

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