Anomalously High Fluorine Mobility in Tysonite-Like LaF3:ScF3 Nanocrystals: NMR Diffusion Data

Nanosized La0.93Sc0.07F3 superionic conductor with tysonite structure was obtained at the gas–solution interface after interaction of aqueous salt solution with gaseous HF. NMR diffusion studies show that homovalent substitution of La3+ by Sc3+ with a smaller ionic radius leads to around four orders of magnitude faster fluorine diffusion as compared with crystalline LaF3 and faster as in all previously studied nanosized LaF3 and heterovalent-doped nanosized La0.95Sr0.05F2.95. The homovalent doping is a new route to improve the conductivity of tysonite-structured nanomaterials.