Study of the Crystallization Fields of Vanadyl(IV) Selenites in the System VOSeO3 - SeO2 - H2O

摘要

The solubility of VOSeO3-SeO2-H2O system was studied within the temperature interval 50-300 °C. The phase diagram of vanadyl(IV) selenites was plotted and the crystallization fields were determined for the different phases. Depending on the conditions for hydrothermal synthesis, several types of selenites were obtained - [VO(SeO3)(H2O)2] · 0.5 H2O, VOSeO3 · H2O, VOSeO3 and VOSe2O5. The different phases were established and characterized by chemical, thermal and powder X-ray diffraction analyses, as well as by IR spectroscopy.