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Phase relations in the ternary oxide system Al2O3-V2O5-MoO3 in the solid state in air have been investigated by using the x-ray diffraction (XRD) and differential thermal analysis/thermogravimetric (DTA/TG) methods. It was confirmed that in the subsolidus area of the Al2O3-V2O5-MoO3 system, there exist seven phases, that is Al2O3, V2O5(s.s.), MoO3, AlVO4, Al2(MoO4)3, AlVMoO7, and V9Mo6O40. Seven fields, in which particular phases coexist at equilibrium, were isolated. The crystal structure of AlVO4 has been refined from x-ray powder diffraction data. Its space group is triclinic, $$ P\bar{1} $$, Z = 6, with a = 0.65323(1) nm, b = 0.77498(2) nm, c = 0.91233(3) nm, α = 96.175(2)°, β = 107.234(3)°, γ = 101.404(3)°, V = 0.42555 nm3. The crystal structure of the compound is isotypic with FeVO4. Infrared (IR) spectra of AlVO4 and FeVO4 are compared. [ABSTRACT FROM AUTHOR]

Phase relations in the solid state in the FeVO4–Co3V2O8 system, in the whole range of components concentration have been studied. It was found that the composition of the phase of the howardevansite type structure, formed in the investigated system, corresponds with the Co2.616Fe4.256V6O24 formula. The phase of the lyonsite type structure has a homogeneity range with the Co3+1.5xFe4–xV6O24 formula (0.476 formula (0.476< x<1.667). The melting temperature and the volume of the unit cell of the lyonsite type structure phase increases together with the rise of cobalt quantity contained in it. Basing on the results of the DTA and XRD measurements a phase diagram of the FeVO4–Co3V2O8 system up to the solidus line was constructed. [ABSTRACT FROM AUTHOR]

A new compound Co3Fe4V6O24 has been obtained by solid state reaction. Temperature of its incongruent melting amounts to 890±5°C. Results of indexing the powder diffraction pattern and unit cell parameters of Co3Fe4V6O24 are also given. This compound is probably isostructural with M3Fe4V6O24 (whereM= Zn, Mg, Mn). IR spectrum of Co3Fe4V6O24 phase is presented. [ABSTRACT FROM AUTHOR]

Reactivity of FeVO4 towards Ni2V2O7 and Ni3V2O8 in the solid state was investigated. On the base of XRD and DTA results, phase diagrams in subsolidus area of the FeVO4-Ni2V2O7 and FeVO4-Ni3V2O8 intersections of the ternary system NiO-V2O5-Fe2O3 have been worked out and the phase diagram of this ternary system in subsolidus area in the whole component concentration range has been verified. [ABSTRACT FROM AUTHOR]

A compound of the formula Fe3Mg2Mo2V3O20 has been obtained as a result of a reaction between FeVO4 and MgMoO4 taken at a molar ratio of 3:2. This compound crystallises in the monoclinic system and its unit cell parameters are the following:a=0.6971 nm,b=0.9055 nm,c=1.2542 nm,g=102.00°,Z=2. [ABSTRACT FROM AUTHOR]

A new compound Co3Fe4V6O24 has been obtained by solid state reaction. Temperature of its incongruent melting amounts to 890±5°C. Results of indexing the powder diffraction pattern and unit cell parameters of Co3Fe4V6O24 are also given. This compound is probably isostructural with M3Fe4V6O24 (whereM= Zn, Mg, Mn). IR spectrum of Co3Fe4V6O24 phase is presented. [ABSTRACT FROM AUTHOR]

Using DTA and XRD methods, a diagram of phase equilibria in ZnV2O6-ZnFe2O4 system has been constructed. System ZnV2O6-ZnFe2O4 is in subsolidus area a real binary system and its components form a compound Zn2FeV3O11. Zn2FeV3O11 melts incongruently at 835±5°C with deposition of two solid phases: b-Zn2V2O7 and ZnFe2O4. [ABSTRACT FROM AUTHOR]

Phase equilibria in subsolidus area in the ZnO-V2O5-Fe2O3 system have been investigated over the whole concentration range of the oxides. The components of this system form two compounds: Zn2FeV3O11 and Zn3Fe4(VO4)6. A solidus area projection onto the component concentration triangle plane of the ZnO-V2O5-Fe2O3 system has been constructed using DTA and XRD methods. 11 subsidiary subsystems can be distinguished in this system. Melting temperatures of mixtures of solid phases coexisting at equilibrium in each of subsidiary subsystems were determined. [ABSTRACT FROM AUTHOR]

Using DTA and XRD methods, a diagram of phase equilibria in ZnV2O6-ZnFe2O4 system has been constructed. System ZnV2O6-ZnFe2O4 is in subsolidus area a real binary system and its components form a compound Zn2FeV3O11. Zn2FeV3O11 melts incongruently at 835±5°C with deposition of two solid phases: b-Zn2V2O7 and ZnFe2O4. [ABSTRACT FROM AUTHOR]

New compounds: Mg3Fe4(VO4)6 and Zn3Fe4(VO4)6 were obtained from a solid state reaction. The temperatures of melting of Mg3Fe4(VO4)6 and Zn3Fe4(VO4)6 amount to 950±5 and 850±5°C, respectively. The indexing results and the calculated unit cell parameters for both compounds are given and suggest that both phases are isotypic with Mn3Fe4(VO4)6. The IR spectra of the above-mentioned compounds are presented. [Copyright &y& Elsevier]

Phase relations in the ternary oxide system Al2O3-V2O5-MoO3 in the solid state in air have been investigated by using the x-ray diffraction (XRD) and differential thermal analysis/thermogravimetric (DTA/TG) methods. It was confirmed that in the subsolidus area of the Al2O3-V2O5-MoO3 system, there exist seven phases, that is Al2O3, V2O5(s.s.), MoO3, AlVO4, Al2(MoO4)3, AlVMoO7, and V9Mo6O40. Seven fields, in which particular phases coexist at equilibrium, were isolated. The crystal structure of AlVO4 has been refined from x-ray powder diffraction data. Its space group is triclinic, $$ P\bar{1} $$, Z = 6, with a = 0.65323(1) nm, b = 0.77498(2) nm, c = 0.91233(3) nm, α = 96.175(2)°, β = 107.234(3)°, γ = 101.404(3)°, V = 0.42555 nm3. The crystal structure of the compound is isotypic with FeVO4. Infrared (IR) spectra of AlVO4 and FeVO4 are compared. [ABSTRACT FROM AUTHOR]