Electrical transport properties of 0.5Li2O-0.5M2O-2B2O3 (M=Li, Na and K) glasses

TL;DR

This study investigates the dielectric and electrical conductivity properties of transparent glasses in the 0.5Li2O-0.5M2O-2B2O3 system, revealing how different alkali ions influence transport mechanisms and activation energies.

Contribution

It provides new insights into the frequency and temperature dependence of dielectric relaxation and conductivity in these glasses, highlighting the mixed cationic effect on activation energy.

Findings

Higher activation energy for LKBO glasses (1.25 eV) compared to others.

Temperature-independent stretching exponent {eta} for LNBO glasses.

Dielectric and conductivity properties characterized over 100 Hz - 10 MHz range.

Abstract

Transparent glasses in the system 0.5Li2O-0.5M2O-2B2O3 (M=Li, Na and K) were fabricated via the conventional melt quenching technique. Amorphous and glassy nature of the samples were confirmed via the X-ray powder diffraction and the differential scanning calorimetry, respectively. The frequency and temperature dependent characteristics of the dielectric relaxation and the electrical conductivity were investigated in the 100 Hz - 10 MHz frequency range. The imaginary part of the electric modulus spectra was modeled using an approximate solution of Kohrausch-Williams-Watts relation. The stretching exponent, {\beta}, was found to be temperature independent for 0.5Li2O-0.5Na2O-2B2O3 (LNBO) glasses. The activation energy associated with DC conductivity was found to be higher (1.25eV) for 0.5Li2O-0.5K2O-2B2O3 (LKBO) glasses than that of the other glass systems under study. This could be attributed to the mixed cationic effect.