Effect of iso- and heterovalent cation substitutions on the superionic Faraday transition in fluorite-type modification β-PbF-=SUB=-2-=/SUB=-

The influence of isovalent substitutions Pb 2+ -> Cd and heterovalent Sc 3+ on a superionic Faraday transition in 1-x x F 2 (x=0.33) 2+x (x=0.1) solid solutions based the fluorite-type modification β-PbF with sp. gr. Fm 3 m has been studied. phase can be characterized by temperature T tr λ corresponding to maximum heat capacity curve α beginning structural disorder anion sublattice. Both these temperatures are found conductivity dependence sigma dc (T) , 0.67 0.33 0.9 0.1 2.1 crystals. values compared (T =715±10 K, = 597±12 K) decrease 100-110 30-45 K for respectively. Decreasing leads an increase interval existence state. For T>T anionic crystals reaches anomalously high 1-2 S/cm (873 at ion transfer activation enthalpy equals H ~0.3 eV. Keywords: transitions, fluorides, fluorite structure, ionic conductivity, solutions.