EFFECTS OF ELECTRONIC BAND ON ACTIVATION-ENERGY AND OF EFFECTIVE CHARGE ON LATTICE DISTORTION IN SUPERIONIC CONDUCTORS

A strong contribution of the electronic energy state near the band gap on superionic conduction is suggested by showing an empirical relatio nship between the optical dielectric constant and the activation energ y, E-ac. The transverse effective charge is connected with the transit ion temperature and E-ac value. On the basis of this charge and the cr ystal symmetry, we can understand the structural phase transition in s uperionic conductors and the non-structural transition in high ionic c onductors AgX (X = F, Cl and Br) and CuF. (C) 1998 Elsevier Science Lt d. All rights reserved.