Transition from ionic to electronic conduction in silver-vanadate-phosphate glasses

A series of silver-vanadate-phosphate glasses of the AgI-Ag2O-V2O5-P2O5 sys tem has been prepared and their electrical properties have been studied. Co mpositions of high AgI content and low V2O5 content exhibited pure ionic co nduction. On the other hand, vanadium-rich and silver-poor glasses were alm ost pure electronic conductors, for which, depending on temperature, the mo dels of phonon-assisted hopping of small polarons or variable range hopping can be applied. Samples of intermediate compositions exhibited mixed ionic -electronic conductivity. The observed transition from ionic- to electronic -type conduction in the frame of the same system could be of interest for p ossible practical applications, e.g. in integrated microbatteries. (C) 1999 Elsevier Science B.V. All rights reserved.