Open AccessRapid characterization of complex structural phase transitions using powder diffraction and an area detector
Author(s) -
Pattison Philip,
Knudsen Kenneth D.,
Cerny Radovan,
Koller Edmond
Publication year - 2000
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049500004210
Subject(s) - synchrotron , manganate , rietveld refinement , powder diffraction , collimated light , materials science , detector , diffraction , lattice constant , bond length , octahedron , perovskite (structure) , crystallography , analytical chemistry (journal) , optics , chemistry , physics , crystal structure , thermodynamics , laser , power (physics) , battery (electricity) , chromatography
The use of a high‐intensity and well collimated X‐ray beam from a third‐generation synchrotron source, combined with an area detector with online readout capabilities, allows high‐quality powder patterns to be obtained with exposure times of only a few seconds. Powder measurements of a rare‐earth manganate perovskite (Nd 0.43 Sr 0.57 MnO 3 ) were performed in the temperature range 105–200 K, and the data were of sufficient quality to be able to extract, via Rietveld refinement, accurate values for the lattice constants and atomic parameters. The temperature dependence of the Mn—O—Mn bond angles and Mn—O distances obtained in this manner illustrate the well known correlation between the distortion of the MnO 6 octahedra and the onset of orbital ordering. The success of this study, for which only two hours of synchrotron beam time was required, indicates the enormous improvements in efficiency and throughput which area detectors are bringing to powder diffraction experiments.