Open AccessNew triple molybdate and tungstate Na5Rb7Sc2(XO4)9 (X = Mo, W)
Author(s) -
Tatyana S. Spiridonova,
Aleksandra A. Savina,
Evgeniy V. Kovtunets,
Elena G. Khaikina
Publication year - 2021
Publication title -
chimica techno acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.128
H-Index - 1
eISSN - 2411-1414
pISSN - 2409-5613
DOI - 10.15826/chimtech.2021.8.4.12
Subject(s) - tungstate , isostructural , molybdate , crystallography , x ray crystallography , powder diffraction , thermal expansion , materials science , crystal structure , rietveld refinement , trigonal crystal system , cerium , molybdenum , diffraction , chemistry , metallurgy , physics , optics
New compounds of the composition Na5Rb7Sc2(XO4)9 (X = Mo, W) were obtained via the ceramic technology. The sequences of chemical transformations occurring during the formation of these compounds were established, and their primary characterization was performed. Both Na5Rb7Sc2(XO4)9 (X = Mo, W) were found to melt incongruently at 857 K (X = Mo) and 889 K (X = W). They are isostructural to Ag5Rb7Sc2(XO4)9 (X = Mo, W), Na5Cs7Ln2(MoO4)9 (Ln = Tm, Yb, Lu) and crystallize in the trigonal crystal system (sp. gr. R32). The crystal structures were refined with the Rietveld method using the powder X-ray diffraction data. The thermal expansion of Na5Rb7Sc2(WO4)9 was studied by high-temperature powder X-ray diffraction; it was shown that this triple tungstate belongs to high thermal expansion materials.