The elaboration of complex approach based on the use of modern theoretical and experimental methods is being continued for the overall investigation of the nature of superionic conductivity in solid electrolytes with predominant anionic conductivity. For the first time by the method of molecular statics (interatomic potentials) the allowing to make the conclusion about the predominant type of intrinsic Shottky disordering in cotunnit-like crystals of PbCl2 type was obtained, as well as the possibility of realization of vacancy mechanism of migration of chlorine ions. The anisotropy of transport properties in these crystals was established. It was shown that the movement of chlorine ions along c axis is more preferable than in a and b directions. As a result of the search of new superionic conductors on the basis of binary systems stannum dichloride - chlorides of alkali metals were synthesized for the first time and trichlorostannat(II) of caesium with unique electrophysical properties was studied (s @ 10-4 ё10-3 Om-1 cm-1 and E@ 0.2 eV in the temperature range 293-473). The investigation of the nature of the appearance of superionic state in solid electrolytes LaF3 with the tysonite-type structure was carried out according to NMR data. The analysis of the form of the 19F NMR spectrum of allowed to investigate in detail the disordering of ionic mobility in LaF3 in the temperature range 190-400K. It was found that local potentials in tysonite crystals have significant space fluctuations, that is expressed in distribution of the correlation times of ionic jumps. The possible reason for the distribution of correlation times can be the local space fluctuation of vacancy density in the crystalline lattice. Theoretical and experimental analysis of the realization of fast ion transport in the inorganic systems under investigation with the predominant anionic conductivity allowed to understand better the nature of superionic state, which is one of the most actual problems of solid state ionics.
|Translated title of the contribution||The nature of superionic conductivity in inorganic halides|
|Publisher||Издательский Центр «Академия»|
|Publication status||Published - 1998|