Arakcheeva, AllaPattison, PhilipChapuis, GervaisRossell, MartaFilaretov, AndrejMorozov, VladimirVan Tendeloo, Gustaaf2008-03-182008-03-182008-03-18200810.1107/S0108768108001870https://infoscience.epfl.ch/handle/20.500.14299/20145WOS:00025399260000411895The incommensurately modulated scheelite-like KSm(MoO4)2 structure has been refined in the monoclinic superspace group I2/b(ab0)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 {KMoO4} to {SmMoO4} observed in the ab structure projection along q. The specific features of KSm(MoO4)2 and degree of the A-cation ordering are discussed in comparison with the previously reported structure of KNd(MoO4)2.incommensurately modulated structureoccupation modulationdegree of orderingscheelite-like structuresanisotropic microstrain line-broadeningtext::journal::journal article::research article