PHASE EQUILIBRIA IN THE V2O3-P2O5-H2O SYSTEM: SYNTHESIS AND CHARACTERIZATION OF SOME VANADIUM(III) PHOSPHATES
2002 年 13 巻 p. 231-234
詳細
2002 年 13 巻 p. 231-234
Using the thin-layer technique, phase equilibria in the open V2O3-P2O5-H2O system have been studied within the temperature range of 25-300°C at the molar ratio P2O5 : V2O3 = (3-10) : 1. The diagram of the crystallization fields for stable phases of vanadium(III) phosphates has been constructed. The following phosphates were synthesized and identified by chemical analysis, X-ray powder diffraction, and thin-layer chromatography: monophosphates V3H15(PO4)8 5H2O and V(H2PO4)3 (form A ), triphosphates VH2P3O10 (forms I, II, III, and IV) and VH2P3O10.2H2O (forms I, III, and IV), cyclotetraphosphate V4(P4O12)3 (form A), polyphosphate V(PO3)3 (form C). XRD data for powder samples of novel vanadium(III) phosphates are given.
