Synthesis, Structure and Electrophysical Properties of Fluoride-Conducting Phases Вa1-XLaXSnF4+X

It has been determined that the concentration interval for the existence of solid solutions of heterovalent substitution Ba1-xLaxSnF4+x, which are formed by the partial replacement of barium cations with lanthanum cations in the BaSnF4 compound, is 0.0<х≤0.12. The obtained phases are isostructural BaSnF4, have a crystal lattice of tetragonal syngony, corresponding to the P4/nmm space group. The change in the values of electrical conductivity and its activation energy is extreme, with a maximum for the composition with lanthanum cation content of 0.07 m.р. and is 3.08∙10–3 S/cm at 623 K and 5.69∙10–4 S/cm at 293 K, respectively. The electrochemical stability window of the synthesized phases is estimated by the potential range of –1.7 ÷ +1.7V.