Conductivity spectra of silver-phosphate glass nanocomposites: Frequency and temperature dependency

Abstract

A series of glass nanocomposite systems of the composition xAgI–(1 − x) (0.5Ag2O–0.5P2O5) for x = 0.1, 0.2, 0.3 and 0.4 have been prepared by conventional melt quenching route. The X-ray diffraction patterns indicate the amorphous nature of all the glassy samples with the presence of a certain amount of crystallinity, superposing over broad peaks. Different types of bonds, existing within present system have been identified by FT-IR measurement. The dc and ac conductivity decreases with AgI content. The values of activation energy for dc conductivity and activation energy for crossover frequency are very close to each other, which specify that the same mechanism is responsible for the electrical conduction. The ionic conduction depends on the Agion–Agion separation (R), which increases with a rise in AgI content. The absence of grain boundary effect is observed from complex impedance plots. The formation of the cation-electron pair with increasing AgI content is expected to block the diffusive or hopping path, which indicates fall in conductivity. Correlated barrier hopping (CBH) model is the appropriate mechanism for ac conduction process. The temperature and composition scaling of conductivity spectra reveals that the conductivity relaxation is independent of temperature but depend on composition i.e., the structure of the glass nanocomposites.