Phase diagrams of the BaF₂–NdF₃ and BaF₂–PrF₃ systems

Phase formation in the BaF 2 –NdF 3 and BaF 2 –PrF 3 systems was studied by solid‐phase annealing at 750°С and syntheses in molten NaNO 3 flux at 500°С. We observed the formation of Ba 1− х R х F 2+ х fluorite solid solutions in the aforementioned systems, and these solid solutions underwent ordering to form ordered Ba 4 Nd 3 F 17 and Ba 4 Pr 3 F 17 fluorite‐like phases at 917°С and 880°С, respectively.