Preparation of fluorides at 80 degrees C in the NaF-(Y,Yb,Pr)F-3 system

Crystalline single-phase hexagonal fluorides with nominal compositions NaY1 -x-yYbxPryF4 (with 0 less than or equal to x less than or equal to 1 and y less than or equal to 0.05) have been prepared by a coprecipitation techniq ue without the need of any thermal treatment as a final step. Compared with the fluorides prepared by solid state chemistry, this protocol allows bett er control of the stoichiometry of the materials and improves the homogenei ty of the grain Size distribution. The influence of these structural and mi crostructural parameters and of the oxygen content on the optical performan ces of these fluorides is examined and discussed by comparison with the spe ctroscopic properties of solid state synthesized Pr3+-doped NaYF4 fluorides .