Dielectric Relaxation and Impedance Spectroscopy of 30V2O5 · 20Bi2O3 · 50P2O5 Glass
M. M. El‐Desoky, Ahmed E. Hannora
Abstract
Dielectric properties of traditionally quenched 30V2O5 · 20Bi2O3 · 50P2O5 glass been investigated at different frequencies in temperature range of 298–573 K. X-ray diffraction (XRD) was used to confirm the amorphous nature of the formed glass and for ion. The thermal analysis was investigated by differential scanning calorimetry (DSC) technique where the temperature stability i.e. Tc–Tg of the glass sample was 207.5 K. This means that the present glass has a high thermal stability. Dielectric constant, dielectric loss, loss tangent, ac conductivity and electric modulus were calculated for the formed glass in the studied temperature range. The prepared glass has a large dielectric constant increase with temperature. The activation energy calculated from dc conductivity Edc, dielectric loss Etan δ and $${{E}_{{{{M}^{{'{\kern 1pt} '}}}}}}$$ modulus frequency relaxation time was 0.180, 0.209 and 0.185 eV, respectively. Activation energy values of Edc and $${{E}_{{{{M}^{{'{\kern 1pt} '}}}}}}$$ are nearly identical, indicate that the ions overcome same energy barrier in conducting and relaxing process. The small value of stretched exponent parameter (β) of 0.061 suggests good correlated motion between the ions of non-Debye-type relaxation. The semicircles formed with Nyquist diagram indicate a single-phase material with electronic type of conduction mechanism.