New Ceramic Material Y2-xVxO3+x - Mechanochemical Synthesis and Some Physicochemical Properties

Potential applications of known compounds from the V2O-Y2O3 system, i. e. YVO4, Y8V2O17 and Y10V2O20, were the inspiration to undertake research, the main goal of which was to determine whether unknown phases of the solid solution type are formed in this system. Solid solutions are still sought-after phases because their properties depend on their chemical composition. In this work it was experimentally demonstrated that a new substitute solid solution with the formula Y2-xVxO3+x (0.00<x<0.60) is formed from mixtures of V2O5 with Y2O3 as a result of mechanochemical synthesis. Its properties were examined by using, i.a. XRD (X-ray diffraction) and UV-Vis-DRS (ultraviolet-visible light spectroscopy with diffusion reflectance) methods. It was found among other things, that it crystallizes in a regular system, exhibits a Y2O3 structure and is thermally stable up to at least 800 degrees C (for x=0.40). Moreover, the estimated value of the band gap width indicated that the solid solution Y2-xVxO3+x belongs to the class of semiconductors. The study of dielectric properties of new phase was performed by means of broadband dielectric spectroscopy. The obtained measurement data showed the presence of relaxation type dielectric mechanisms. The thermally activation energies of the relaxation processes related to the electric conductivity were calculated.