COMPOSITION DEPENDENT ELECTRICAL-CONDUCTIVITY OF ESS-THAN-OR-EQUAL-TO-Y-LESS-THAN-OR-EQUAL-TO-0.70, AL-TO-X-LESS-THAN-OR-EQUAL-TO-0.4(X)AG2O.P2O5]YAGI GLASSES IN THE RANGE 0.55)

Glasses of the following general formula were prepared in order to inv estigate their electrical and thermal properties: (1-y) [(1+x) Ag2O.P- 2 O-5]yAgI, 0.55 less than or equal to y less than or equal to 0.70, 0 less than or equal to x less than or equal to 0.4. Experimental data confirm that, as reported in the literature, the increase of the AgI c ontent makes the electrical conductivity, sigma, increase and the glas s transformation temperature T-g decrease. The increase of sigma is pr imarily due to the decrease of the activation energy for conduction, E (sigma). The results can be interpreted on the basis of the model repo rted in the literature of a glass demixed in AgI microdomains and a ph osphate matrix. They suggest that the Ag+ migration paths also involve sites other than the ones near I- ions and that E(sigma) for the AgI doped glasses can be considered an average of the values relative to t he various phases present. As it happens in glasses poorer in AgI cont ent, a linear relation is observed when the ratio E(sigma)/E(sigma ma) of the activation energies of AgI doped, E(sigma) and undoped, E(sigm a ma) glasses is plotted against the fraction of Ag+ ions introduced a s Ag2O.