Analysis of solid solutions stability in scheelite-type molybdates and tungstates

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.08.003· OSTI ID:21580038

Patrusheva, T A

Mutual solubility of bivalent metal molybdates and tungstates with scheelite structure was theoretically estimated by calculating formation enthalpies and the maximal decomposition temperatures of solid solutions at different temperatures. The theoretical stability of continuous solid solutions in binary systems of bivalent metal molybdates and tungstates was found to be higher than reported literature data. After cooling down continuous substitution solid solution should remain in following systems: CaMoO{sub 4}-CdMoO{sub 4}, SrMoO{sub 4}-MMoO{sub 4} (M=Ba, Pb), BaMoO{sub 4}-PbMoO{sub 4}, SrWO{sub 4}-MWO{sub 4} (M=Ca, Pb), and BaWO{sub 4}-PbWO{sub 4}. There is a probability that at room temperature in systems CaMoO{sub 4}-SrMoO{sub 4,} CaWO{sub 4}-PbWO{sub 4}, and BaWO{sub 4}-SrWO{sub 4} the single homogeneity region may decompose to limited solid solutions. It was shown experimentally that a continuous series of scheelite-structure solid solutions M{sub 1-x}M{sup I}{sub x}TO{sub 4} can be formed via citrate synthesis at temperatures below 500 deg. S. - Graphical abstract: Calculated boundaries of solid solutions in BaWO{sub 4}-CaWO{sub 4} (1) and PbMoO{sub 4}-CaMoO{sub 4} (2) systems. Highlights: > Stability of solid solutions molybdates and tungstates has been investigated. > The ionic model for isovalent substitutions was used. > In 'polyhedral substitution model' enthalphies of mixing were calculated. > Most of the examined series of solid solutions is stable at room temperatures. > Solid solutions M{sub 1-x}M{sup I}{sub x}Mo(W)O{sub 4} (x=0-1) were formed via citrate synthesis below 500 S.

• OSTI ID: 21580038
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 10; Other Information: DOI: 10.1016/j.jssc.2011.08.003; PII: S0022-4596(11)00428-2; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BARIUM TUNGSTATES
CALCIUM TUNGSTATES
FORMATION HEAT
LEAD TUNGSTATES
MOLYBDATES
SOLID SOLUTIONS
SOLUBILITY
STABILITY
STRONTIUM TUNGSTATES
SYNTHESIS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
DISPERSIONS
ENTHALPY
HOMOGENEOUS MIXTURES
INORGANIC PHOSPHORS
LEAD COMPOUNDS
MIXTURES
MOLYBDENUM COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORS
PHYSICAL PROPERTIES
REACTION HEAT
REFRACTORY METAL COMPOUNDS
SOLUTIONS
STRONTIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TUNGSTATES
TUNGSTEN COMPOUNDS