Synthesis, Ionic Mobility, and Conductivity of Composites Based on Tin and Lead Difluorides According to the 19F NMR and Impedance Spectroscopy Data

Abstract

The ionic mobility and conductivity of composites and compounds of the eutectic and close composition obtained by different methods in the PbF₂–SnF₂ system are studied based on the ¹⁹F NMR and impedance data. The stages of transformation of the ¹⁹F NMR spectra of these samples, their connection with the types of ionic movements, and the possible factors determining their ionic conductivity are considered. It is shown that the composition of the majority of composites includes the fluorite phase characterized by the high values of ionic mobility and conductivity. In the region close to the eutectic, a single-phase sample with the fluorite structure is obtained for the first time. The conductivity of this phase (5 × 10^–3 S/cm at 390 K) makes it possible to consider it as the basis for synthesizing functional materials.