The short-range structure and hydration process of fluorine-substituted double perovskites based on barium-calcium niobate Ba2CaNbO5.5

In this work the influence of fluorine substitution on the structure and hydration processes of solid solutions Ba2-0.5xCaNbO5.5-xFx and Ba2CaNbO5.5-0.5yFy with different concentration of oxygen vacancies was investigated. It was found that fluorine substitution leads to the decrease in the cell volume due to the decrease in niobium-oxygen bond length. The possibility of water uptake was proved, the introduction of fluorine leads to decrease in concentration of protons and to increase in hydrogen bonds.