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

A new approach to anionic conduction is presented, and illustrated using al ready well-known anion conductors, as well as the recently discovered fast oxide-ion conductor La2Mo2O9. The so-called LPS (lone-pair substitution) co ncept 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 si milarity in volume between an electronic lone pair and oxide or fluoride an ions, 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 el ements for given lone-pair cations is presented. (C) 2000 Editions scientif iques et medicales Elsevier SAS. All rights reserved.