Transport properties of solid solutions PbF2–SnF2–SbF3 prepared by solid state techniques

Abstract

The ionic mobility and electrical conductivity in solid solutions with the fluorite structure obtained by the solid-phase method in the system PbF2–SnF2–SbF3 with composition close to PbSnF4 have been investigated using the methods of 19F NMR and impedance spectroscopy. It has been established that parameters of 19F NMR spectra, types of ionic motions in the fluoride sublattice and the value of ionic conductivity are determined by temperature and the composition of the solid solutions. Transport properties of solid solutions under study are similar to those of tetragonal phase β-PbSnF4. It suggests that fluorite phase in solid solutions under study is metastable and formed by elementary fluorite-type blocks typical of the structure of β-PbSnF4. Introduction of Sb3+ into the structure leads to decrease in the conductivity. Nevertheless, the specific conductivity of solid solutions in the system and PbF2–SnF2–SbF3 at 400K attains the values of 10−2–10−3S/cm, which enables one to consider them as promising materials for electrochemical applications.