KSm(MoO(4))(2), an incommensurately modulated and partially disordered scheelite-like structure.
The incommensurately modulated scheelite-like KSm(MoO(4))(2) structure has been refined in the monoclinic superspace group I2/b(alphabeta0)00 by the Rietveld method on the basis of synchrotron radiation powder diffraction data. The systematic broadening of satellite reflections has been accounted for by applying anisotropic microstrain line-broadening. The microstructure has been studied by transmission electron microscopy (TEM). The partial disorder of the K and Sm cations in the A position is best approximated by a combination of harmonic and complex crenel functions with (0.952Sm + 0.048K) and (0.952K + 0.048Sm) atomic domains. This combination yields a compositional wave distribution from {KMoO(4)} to {SmMoO(4)} observed in the ab structure projection along q. The specific features of KSm(MoO(4))(2) and degree of the A-cation ordering are discussed in comparison with the previously reported structure of KNd(MoO(4))(2).
Arakcheeva
Alla
A
Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Cristallographie, BSP, CH-1015 Lausanne, Switzerland. alla.arakcheeva@epfl.ch
Pattison
Philip
P
Chapuis
Gervais
G
Rossell
Marta
M
Filaretov
Andrey
A
Morozov
Vladimir
V
Van Tendeloo
Gustaaf
G