Preparation of barium monohydrofluoride BaF2·HF from nitrate aqueous solutions

Abstract Barium ions react with HF in aqueous media, forming BaF 2 ·HF for >0.7 wt.% aqueous HF instead of the expected BaF 2 precipitates. Optimal yields of BaF 2 ·HF have been obtained with the use of concentrated Ba(NO 3 ) 2 (0.8 М) and HF (26.0 М) aqueous solutions, using more than 2 equiv. of the latter. The composition, morphology and particle size of the formed precipitates are dependent upon the synthetic conditions, such as concentrations of starting materials, their stoichiometry and order of addition. BaF 2 ·HF is an excellent precursor for the preparation of optical fluoride ceramics having high transparency in the 0.3–12 μm range, and scintillator ceramics (e.g., BaF 2 or BaF 2 :Ce 3+ ) as well.