AC/DC conductivity studies of composites of glassy electronic and ionic conductors

A series of all-glass composites has been prepared from the ionically conducting silver-phosphate glass 30AgI·35Ag2O·35P2O5 (denoted as I) and the electronically conducting vanadate-phosphate glass 90V2O5·10P2O5 (denoted as E). Component glasses were ground, mixed in five volume ratios (E:I = 3:1, 2:1, 1:1, 1:2, 1:3) and pelletized under pressure. X-ray diffractometry and DSC analyses confirmed an amorphous structure of both component glasses and all final composites. Electrical properties were investigated using DC (Hebb-Wagner polarization method) and AC (impedance spectroscopy) methods. The analysis of the impedance spectra (measured down to μHz) evolution with the proportions of the electronic-to-ionic component was done. Mixed character of the conductivity was confirmed and a synergy effect (charge storage capacity) arising from the interface interactions between glasses was observed.