Browsing by Author "Bancheva T."

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    On the formation of solid solutions of blödite- and kröhnkite-type structures. Iv. Synthesis, structural, spectroscopic and thermal investigations of Na2Co1-Xmgx(So4)2•4H2O (0 < X < 1)
    (2017-01-01) Georgiev M.; Marinova D.; Bancheva T.; Stoilova D.
    New structural, spectroscopic and thermal data on the formation and characterization of solid solutions containing cobalt blödite, Na2Co(SO4)2•4H2O, and magnesium blödite, Na2Mg(SO4)2•4H2O, are provided in this contribution. On the basis of the solubility data and X-ray powder diffraction it is found that both compounds form a continuous series of solid solutions due to their isostructureness. It is established that the lattice parameters of the solid solutions obey the Vegard rule. The infrared spectra of the blödite phases are interpreted in the light of their crystal structures. The strength of the hydrogen bonds in both hydrates and in the solid solutions is analyzed in terms of matrix infrared spectroscopy (matrix-isolated HDO molecules). The thermal behavior and phase transitions of the solid phases are studied by TG and DTA analyses. It is found that the dehydration processes occur stepwise forming thus intermediate hydrates and anhydrous compounds at 350°C.