Ionic conductivity of all-glass composites in the AgI-Ag2O-P2O5 system

All-glass composites fabricated from mixtures of the superionic 33AgI center dot 33Ag(2)O center dot 33P(2)O(5) and 60AgI center dot 20Ag(2)O center dot 20P(2)O(5) glasses conduct Ag' ions. It is demonstrated that such composites can be easily formed by high-pressure methods. Their electric properties could be modelled by an equivalent electric circuit in which the ion conductivity of the bulk of a composite is represented by a single 'effective resistance'. A related quantity-the effective ion conductivity, shows Arrhenius-like dependence. The effective activation energy and the effective preexponential factor both exhibit linear dependence on composition. The general mixing rule and the Uvarov model appeared to be unsuitable for the description of the effective conductivity of the all-glass composites as a function of composition and temperature. A new phenomenological model of effective conductivity is suggested and tested-proving its applicability. (c) 2007 Elsevier B.V. All rights reserved.