Frequency domain measurements on Na2B4O7−V2O5 semiconducting glass

Abstract

Summary. --Dielectric measurements on NaeB407(99.5%)-VeOs(0.5%) glass system, in the frequency range 10-8 to 104 Hz and temperature range 300 to 500 K, have been carried out. The normalized plots of complex capacitance have shown a single mechanism responsible for conduction for both volume and surface measurements with their close values of activation energies (0.67 + 0.03) eV and (0.64 _+ 0.03)eV, respectively. The low-frequency dispersion (LFD) behaviour has been observed to be perturbed by the presence of more than one competing process. The impedance plots have shown a parallel combination of a capacitor (C) and a resistor (R), with some contribution of a dispersive element due to charge accumulation in the vicinity of the electrodes. The values of R and C were found to be of the same order of magnitude, for both surface and volume measurements. The observed R has shown a decrease with an increase in temperature due to an increase in mobility of Na § ions, whereas C remains practically constant. The complex capacitance surface behaviour is dominated by volume, due to hygroscopy of this glass system. PACS 72.80 -Conductivity of specific semiconductors and insulators. PACS 77.40 -Dielectric loss and relaxation.

Interfacial barrier contribution in Na2B4O7 glass system

“…The dispersive nature of the experimen- tal results shown in fig. The basic dielectric response of sodium tetraborate glass system, including t h e eai'lier reported work [18] on NaeBt O7(99.5%)-V205(0.5%), is almost the same, which indicates a bulk conduction process in parallel with a constant, bulk, capacitance, the two being in series with the electrode barrier layer. The basic dielectric response of sodium tetraborate glass system, including t h e eai'lier reported work [18] on NaeBt O7(99.5%)-V205(0.5%), is almost the same, which indicates a bulk conduction process in parallel with a constant, bulk, capacitance, the two being in series with the electrode barrier layer.…”