IR spectroscopic and Crystal morphology studies of the STRUCTURE of alakli metal fluorophosphatozirconates (hafnates)
M. M. Godneva, O. A. Zalkind, A. T. Belyaevskii
I. V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials KSC, Apatity
Keywords: fluorophosphatozirconates, fluorophosphatohafnates, potassium, rhubidium, caesium, chemical bonds, layered crystals
Abstract
Potassium, rhubidium, and caesium fluorophosphatozirconates (hafnates) and oxo(hydroxo)fluorophosphatonitratometalates with PO43-/Zr molar ratios of 2.0, 1.5, 1.0, 0.66, 0.5, and 0.33 are synthesized for the first time. Most of them form either fine crystalline or X-ray amorphous particles. In order to characterize them IR spectroscopy and SEM are used. For the crystalline compounds the types of PO4 groups and the character of bonds between fluorine and water are revealed. The occurrence of triple МеF4×Rb(PO4)0.33×RbNO3 (Ме = Zr, Hf) salts and also M3Me3(PO4)5×3HF crystalline solvates is found. The layered habit of K3Hf3(PO4)5×3HF, RbHfF2PO4×0.5H2O, Rb3Hf3(PO4)5×3HF, CsHfF2PO4×0.5H2O, CsHf2F6PO4×4H2O, and CsH2Hf2F2(PO4)3×2H2O crystals gives grounds to suppose that the structure of these compounds is layered unlike the structure of triple МеF4×Rb(PO4)0.33×RbNO3 salts.
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