Preparation of Strontium Vanadate Sr3V2O8 as Additive to Bi-Based Superconductors
The phase evolution and properties of strontium vanadate Sr3V2O8 were investigated using different method of preparation: solid state reaction and two wet-route techniques (colloidal route and sol-gel method - polymerized complex route). DTA/TG study showed decomposition temperatures of starting materials and helped to choose processing temperatures. XRD analysis was used to determine phase evolution. Solid state reaction sample contained a small amount of Sr3V2O8 as soon as after the first calcinations, but 100% of Sr3V2O8 did not appear until whole procedure was finished. Colloidal route turned out as an inconvenient method for preparation of pure phase. The final colloidal route sample contained 80% of Sr3V2O8, residual volume corresponded to Sr10V6O25. The most progressive phase evolution was detected in the sol-gel route. Raman an FTIR spectroscopy detected evolution of the first amount of Sr3V2O8 after gel heating at 250°C for 2 hours. The pure strontium vanadate was prepared after heating at 800°C for 2 hours.