Influence of purity of NdF3 single crystals on their ionic conductivity

Single crystals of the NdF3 superionic conductor have been grown by the Bridgman method from a melt in a helium atmosphere using a fluorinating PbF2 agent. Commercial NdF3 reagents of special purity grade, reagent grade, and pure grade are used. It is found that the ionic conductivity σ of the crystals depends considerably on the purity grade of the starting substances: at 200°C σ = 1.4 × 10−, 3 × 10−4, and 8 × 10−4 S/cm for reagents of special purity grade, reagent grade, and pure grade, respectively.