Structural unpinning number, basicity and reciprocal electronegativity; their equivalence as ionic conductivity determinants

Abstract

An attempt has been made to extend the structural unpinning concept originally proposed for Ag⁺-ion based fast ion conducting (FIC) glasses to other FIC systems based on Na⁺ or Li⁺ ions. Variation of the log(s), at a given temperature, as a function of structural unpinning number, S, reciprocal average electronegativity (anionic (χ_a) or molecular (χ_m)), optical basicity of glasses, λ, has been examined for a number of Na⁺-ion conducting glasses and a nearly identical behavior has been noticed in all the plots, which suggests the equivalence of these chemical parameters as determinants of the conductivity behavior of glasses.