Analysis of AC Conductivity Data of the Anion Excess Sr1 ? xThxF2 + 2x Solid Solution with Fluorite-Type Structure

Autor: E.F. Hairetdinov, Jean-Maurice Réau, Y. J. Xu, N. F. Uvarov
Rok vydání: 1997
Předmět:
Zdroj: physica status solidi (b). 203:17-27
ISSN: 1521-3951
0370-1972
DOI: 10.1002/1521-3951(199709)203:1<17::aid-pssb17>3.0.co;2-y
Popis: Conductivity parameters, number of charge carriers, frequency of hopping, have been determined from an analysis of ac conductivity data of the Sr 1-x Th x F 2+2x (0 ≤ x ≤ 0.225) solid solution with fluorite-type structure. The charge carrier concentration has been estimated: (i) from the frequency dependence of condoctivity, in accordance with the Almond-West approach; (ii) from the increment of the dielectric constant due to charge carriers. Similar results have been obtained by both approaches. The fraction of charge carriers per formula unit, evaluated as a function of composition, is in good agreement with the estimations made on the basis of the clustering process model which assumes that the charge carriers at long range in Sr 1-x Th x F 2+2x are interstitial fluoride ions of F'''type. For x < 0.05, the results have been interpreted by the additional presence of nn and nnn dipoles, the concentration and reorientation rate parameters of which have been evaluated.
Databáze: OpenAIRE
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