A new metal oxide glassy ceramic system 0.3Li2O–(0.7) (0.5MoO3–0.4V2O5–0.1ZnO) and its crystalline counterpart have been prepared by melt quenching and a slow cooling route, respectively. Over a broad temperature and frequency range, the temperature and frequency-dependent conductivity of both nanocomposite samples have been studied. Conductivity, depending on temperature, is well established using Jonscher’s universal power law, and the frequency dependency is predicted by Almond–West formalism. The DC conductivity (σdc), hopping frequency (ωH), and frequency exponent (n) have been figured out. The high-frequency dispersion in the spectra of AC conductivity is indicated by the frequency exponent (n) value, which represents the dimensional motions of polarons or charge carriers. The movement of polaron with the energy level in the optical band gap is primarily responsible for the predictable values of activation energy corresponding to AC and DC conductivity (Eac and Edc) and the free energy of polaron migration (EH). The complex impedance (cole–cole) plots defend the nature of conduction observed from AC conductivity spectra. The dielectric properties have been investigated in a wide range of temperatures and frequencies by plotting the frequency-dependent dielectric constant εʹ (real) and dielectric loss εʺ (imaginary) which ensures an understanding of the origin and nature of losses occurring in these materials.

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Comparative Analysis of the Electrical and Dielectric Characteristics of a Novel Glassy Ceramic and Its Crystalline Analogue

  • Aditi Sengupta,
  • Sanjib Bhattacharya,
  • Chandan Kumar Ghosh

摘要

A new metal oxide glassy ceramic system 0.3Li2O–(0.7) (0.5MoO3–0.4V2O5–0.1ZnO) and its crystalline counterpart have been prepared by melt quenching and a slow cooling route, respectively. Over a broad temperature and frequency range, the temperature and frequency-dependent conductivity of both nanocomposite samples have been studied. Conductivity, depending on temperature, is well established using Jonscher’s universal power law, and the frequency dependency is predicted by Almond–West formalism. The DC conductivity (σdc), hopping frequency (ωH), and frequency exponent (n) have been figured out. The high-frequency dispersion in the spectra of AC conductivity is indicated by the frequency exponent (n) value, which represents the dimensional motions of polarons or charge carriers. The movement of polaron with the energy level in the optical band gap is primarily responsible for the predictable values of activation energy corresponding to AC and DC conductivity (Eac and Edc) and the free energy of polaron migration (EH). The complex impedance (cole–cole) plots defend the nature of conduction observed from AC conductivity spectra. The dielectric properties have been investigated in a wide range of temperatures and frequencies by plotting the frequency-dependent dielectric constant εʹ (real) and dielectric loss εʺ (imaginary) which ensures an understanding of the origin and nature of losses occurring in these materials.