This work studies the direct current breakdown characteristics of unfilled epoxy and epoxy nonconductive nanocomposites (${\mathrm{S}\mathrm{i}\mathrm{O}}_2,\mathrm{M}\mathrm{g}\mathrm{O}$ and ${\mathrm{A}\mathrm{l}}_2{\mathrm{O}}_3$). It also examines the variation of electrical properties in epoxy nanocomposites. The novel aspect of this study is that the samples of Epoxy nanocomposite were exposed to high voltages of up to six kilo volts for three hours using field electron microscopy under high vacuum conditions (${10}^{-5}$ mbar). The current emitted from these samples was measured at three different intervals of time. In addition, the influence of high voltage on the permittivity, loss factor (tan(δ)), and conductivity of the epoxy nanocomposite was studied. This evaluation was conducted before and after applying the voltage at room temperature, The frequency range extends from ${10}^{-2}$–${10}^{-7}$ Hz using the Novo Control Alpha-A analyzer. Current–voltage characterization was performed through field electron microscopy. The samples were characterized by scanning electron microscopy–energy dispersive X-ray spectroscopy and Fourier Transform Infrared Spectroscopy. The unfilled epoxy exhibited structural degradation, resulting in the formation of holes when exposed to high voltages of up to six kilo volts, leading to a reduction in electrical properties. Nevertheless, the addition of nanoparticles shows a significant increase in the operational lifetime of the epoxy nanocomposite. The degree of increase in the lifetime of epoxy composite varied depending on several factors such as the type of NPs introduced and their respective sizes. The epoxy/${\mathrm{A}\mathrm{l}}_2{\mathrm{O}}_3$ nanocomposite comparing with epoxy/MgO and epoxy/${\mathrm{S}\mathrm{i}\mathrm{O}}_2$ nanocomposite showed elevated resistance to direct current breakdown strength and maintaining its dielectric.

The electrical characteristics of cadmium phosphate glasses doped with varying concentrations of sodium chloride [Cd₃(PO₄)₂]_1-x[NaCl]_x, where x = 0, 2, 4 ,6 mol.% NaCl, were investigated with respect to both dopant levels and temperature. Electrical impedance spectroscopy was employed, and impedance measurements were taken across the frequency spectrum from 10² Hz to 10⁶ Hz. Samples were characterized by scanning electron microscopy–energy dispersive x-ray spectroscopy, x-ray diffraction analysis and Fourier Transform Infrared Spectroscopy. The findings revealed a decrease in bulk resistance with increasing temperature and dopant concentration, indicating a rise in DC-conductivity and suggesting a semiconducting behavior in the material. Moreover, the activation energy values were noted to decrease as dopant concentration increased. Analysis of the AC-conductivity variation with frequency delineated two distinct regions: a low-frequency region where AC-conductivity increased with frequency, indicative of a "pumping force" effect aiding charge carrier movement through various conduction states, and a high-frequency region or frequency-independent zone signifying a transition towards a more ohmic behavior in the material. The study highlighted a decrease in both the dielectric constant and dielectric loss with rising temperature and frequency across all dopant concentrations. Furthermore, the Reaction Coefficient "s" was found to be less than one, suggesting that the conduction mechanism can be elucidated in terms of the Correlated Barrier Hopping (CBH) model.

The ionic and dielectric behavior of (AgPO₃)_{(1 – x)}–NaI_x (x = 0, 0.02, 0.04, …, 0.14) systems were tested in the frequency range of 1–10⁶ Hz at different temperatures using impedance spectroscopy technique. Samples were prepared using the melt quenching method to obtain the desired ratios between NaI and AgPO₃. Results of impedance measurements showed a switching from resistive-like (at low frequency) to capacitive-like (at higher frequency) behavior with a single relaxation peak that shifts to higher frequency with increasing either the temperature or the dopant concentration. In addition, the Nyquist plots showed a decrease in the values of the bulk resistance of the samples with increasing temperature and dopant concentration. The measured AC-conductivity shows a cross-over at frequency f > 10⁵ Hz. The conductivity shows an increase as function of temperature regardless the frequency range and it is almost constant at low frequency up to the crossover frequency, in addition to that, the power law dispersive behavior was also observed at higher frequency ( f > 10⁵ Hz). The DC-conductivity can be explained in terms of silver ions successful diffusion process that take place due to the applied alternative electric field. On the other hand, the diffusion controlled relaxation (DCR) model can be used to explain the power law conductivity. Finally, the values of the activation energy calculated from the linear plot of Arrhenius equation were found to decrease with the dopant concentration from 0.65 eV at zero concentration to 0.36 eV at 14% concentration.