Thermal stability of Ba1-xCaxF2 solid solutions

Ba1-xCaxF2 samples with fluorite-type structure were prepared by high-energy ball milling. DSC measurements revealed exothermic decomposition at temperatures of about 450 °C. Decomposition was also observed by high temperature X-ray experiments. As a product, two phases with compositions close to pure BaF2 and CaF2 were obtained. The decomposition temperature observed by X-ray measurements is lower than in the DSC experiments. This might indicate that X-ray irradiation could foster the decomposition