DTA and XRD methods were applied in studies on phase equilibria established in the system V9Mo6O40-AlVMoO7 up to 1000C over the whole component concentration range. The results were presented in the form of a phase diagram.
It has been shown by the methods of X-ray powder diffraction (XRD), differential thermal analysis (DTA) and infrared spectroscopy
(IR) that solid solutions of a formula Cr1−xAlxVMoO7, where x& (0−0.65), are formed in the system CrVMoO7-AlVMoO7. The obtained research results have proven that the ions Al3+ are incorporated into the crystal lattice of CrVMoO7 instead of Cr3+, which causes a contraction of the lattice and a shift of IR absorption bands towards higher values of wavenumbers. The phases
Cr1−xAlxVMoO7 melt incongruently in the temperature range from 710C (for x=0.65) to ∼820C in the case of x close to zero
The phase equilibria in the solid state in the system AlVO4−MoO3 were determined by DTA and XRD methods. The experimental results are presented in the form of a phase diagram. In the subsolidus
area, the system AlVO4−MoO3 is a real two-component system only within the range AlVO4−AlVMoO7.