Ionic Mobility and Conduction in the 50PbF_2 ·30BiF_3 ·20NaF Solid Solution Studied by NMR and Impedance Spectroscopy

摘要

Ionic mobility and electrical transport in the 50PbF_2 • 30BiF_3 • 20NaF fluorite solid solution have been studied by ~(19)F and ~(23)Na NMR and impedance spectroscopy. Analysis of the NMR spectra allowed us to assess the temperature effect on the nature of ion motion in the fluorine and sodium sublattices, to identify the types of ionic mobility, and determine the corresponding temperature ranges. The results demonstrate that, at temperatures above 390 K, the dominant type of ion motion in 50PbF_2 • 30BiF_3 • 20NaF is the diffusion of fluoride and sodium ions. The ionic conductivity of the solid solution reaches 4.4 x 10~4 S/cm at 535 K, suggesting that the 50PbF_2 • 30BiF_3 • 20NaF solid solution can be used as a key component for engineering new functional materials.