The LPS concept, a new way to look at anionic conductors

A new approach to anionic conduction is presented, and illustrated using already well-known anion conductors, as well as the recently discovered fast oxide-ion conductor La2Mo2O9. The so-called LPS (lone-pair substitution) concept could be used to seek for novel families of anion conductors, issued from already known compounds with lone-pair elements. It is based on the similarity in volume between an electronic lone pair and oxide or fluoride anions, and on the vacancy created by the replacement of a lone-pair by a non-lone-pair cation. A tentative list of the most appropriate substituting elements for given lone-pair cations is presented. (C) 2000 Editions scientifiques et medicales Elsevier SAS. All rights reserved.