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NMR Study of Internal Motions in a New Family of Ionic Conductors M 2 SbF 5
Author(s) -
Moskvich Yu. N.,
Cherkasov B. I.,
Polyakov A. M.,
Sukhovskii A. A.,
Davidovich R. L.
Publication year - 1989
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221560225
Subject(s) - isostructural , ion , chemistry , conductivity , relaxation (psychology) , ionic conductivity , fast ion conductor , ionic bonding , anisotropy , diffusion , electrical resistivity and conductivity , isotropy , octahedron , nmr spectra database , fluorine , analytical chemistry (journal) , crystallography , spectral line , crystal structure , thermodynamics , electrolyte , organic chemistry , physics , psychology , social psychology , electrode , quantum mechanics , astronomy
19 F NMR spectra and relaxation times T , 1 , T 2 , T 1e and electric conductivity in isostructural polycrystalline pentafluoroantimonates (III) M 2 SbF 5 (M = Rb, K, Cs, Tl, NH 4 ) are measured. It is found that the observed changes in the NMR spectra and relaxation times with temperature are determined by three types of motion: anisotropic and isotropic reorientations of [SbF 5 E] 2− octahedra and diffusion motion of the fluorine ions. Parameters of these motions are found. All the compounds investigated show high conductivity at high temperature, amounting in the case of thallium and ammonium salts the values of σ = 10 1 to 10 0 Ω −1 m −1 typical of superionic crystals. It is shown that the observed high conductivity is determined by fast diffusion motion of fluorine ions. On the basis of the data obtained a mechanism of fluorine ion diffusion is proposed. In (NH 4 ) 2 SbF 5 at 398 K a phase transition is found.