Electrical conductivity of aliovalent substitution solid solution Pb1−xSmxSnF4+x

Abstract

The paper presents results of studies of the conductivity of aliovalent substitution solid solutions, which are formed in the system (1−x)PbF2 — xSmF3 — SnF2 in the concentration range 0 < x ≤ 0.2 mole fraction and have a crystal lattice of hexagonal system isostructural with β-PbSnF4. At a low aliovalent substituent content (x ≤ 0,07), the conductivity of the synthesized fluorides is by an order of magnitude lower than that of β-PbSnF4. At a higer content, it increases and reaches the largest values at x = 0.15. The fluorine anions in the synthesized samples of solid solutions are in three structurally nonequivalent positions, which differ in local environment and the nature of the M-F bond. The conductivity of the synthesized samples is provided by highly mobile interstitial fluorine anions.