The conductivity was measured as a function of composition, temperature and frequency. The degree of enhancement of the conductivity was generally of the order of 50-fold, although an enhancement which amounted to 3 orders of magnitude was sometimes found (table 224). The degree of enhancement was markedly dependent upon the size of the dispersed particles. For a given particle size, the various additions gave different degrees of enhancement. It was concluded that the enhancement arose from bulk, rather than grain-boundary or surface, conduction effects. It was suggested that the dispersed particles led to the generation of an excess of lattice defects, such as Ag+ ion vacancies, in the AgI-Al2O3 system. The excess defects were then expected to enhance the conductivity.

K.Shahi, J.B.Wagner: Journal of Solid State Chemistry, 1982, 42[2], 107-19

Table 224

Ionic Conduction Parameters for AgI-AgBr