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ADPD: a new approach to shared‐site problems in crystallography
Author(s) -
Moroney L. M.,
Thompson P.,
Cox D. E.
Publication year - 1988
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889887010422
Subject(s) - diffraction , dispersion (optics) , wavelength , crystallography , atom (system on chip) , absorption (acoustics) , powder diffraction , materials science , ceramic , x ray crystallography , x ray , optics , chemistry , physics , computer science , optoelectronics , composite material , embedded system
From the anomalous dispersion of X‐rays close to the Zr and Y absorption edges it has been found that individual cation B factors can be determined independently in a refinement of the structure of an yttria‐stabilized zirconia ceramic material with composition Zr 0.81 Y 0.19 O 1.90 . With X‐ray powder data collected at a single wavelength this is not possible because of the high correlations. Simultaneous refinement of data collected at three different X‐ray wavelengths [0.7726(1), 0.7283(1) and 0.6892(1) Å] has allowed the determination of separate mean‐square displacements for each atom, the respective values are 0.045(2) for Zr 4+ , 0.024(6) for Y 3+ and 0.098(2) Å 2 for O 2− . The results indicate that the structural configuration of Zr 4+ is significantly different from that of Y 3+ . This anomalous‐dispersion powder diffraction (ADPD) technique should be of general application to similar shared‐site problems of this kind.