Temperature dependent electrical transport characteristics of BaTiO3 modified lithium borate glasses

Abstract

The glass samples with composition (70B2O3-29Li2O-1Dy2O3)-xBT; x = 0, 10 and 20 weight percent, have been prepared by conventional melt quench technique. The dielectric measurements as a function of temperature have been carried out on these samples in the frequency range 1 Hz-10 MHz. The dielectric relaxation characteristics of these samples have been studied by analyzing dielectric spectroscopy, dielectric loss, electric modulus formulation and electrical conductivity spectroscopy. It is found that the dielectric permittivity of the samples increases with an increase in the temperature and BT content. The frequency dependent ac conductivity has been analyzed using Jonscher’s universal power law whereas non exponential KWW function has been invoked to fit the experimental data of the imaginary part of the electric modulus. The values of the activation energy determined from the electric modulus and that from dc conductivity have been found to be quite close to each other suggesting that the same type of charge barriers are involved in the relaxation and the conduction mechanisms. The stretched exponent (β) and the power exponent (n) have been found to be temperature and composition dependent. The decrease in n with an increase in temperature further suggested that the ac conduction mechanism of the studied samples follows the correlated barrier hopping (CBH) model.

Dielectric Modulus and Conductivity Scaling Approach to the Analysis of Ion Transport in Solid Polymer Electrolytes

“…The low‐frequency region of M ″ peak determines the range in which the charge carriers are confined to potential wells and mobile for very short distances, which is where ac conductivity dominates. Hence, the frequency range where the relaxation peak occurs suggests the transition region from long‐range to short‐range mobility of charge carriers . This relaxation peak moves toward higher frequency with increasing temperature.…”

Effect of Temperature on the Dielectric and Magnetic Properties of NiFe2O4@MgFe2O4 and ZnFe2O4@MgFe2O4 Core-Shell

“…• In the correlated barrier hopping (CBH) model [42], a temperature-dependence of exponent (s) and decreases with the increase in temperature.…”

“…6. The conductivity mechanism for any material could be explained by the temperature-dependent behavior of (s) [41][42]. In other words, the relation between the temperature and the value of (s) gives a good knowledge about the charge transport mechanism in dielectric substances.…”

Study of barium titanate/nickel-zinc ferrite based composites: Electrical and magnetic properties and humidity sensitivity

“…Deviations from the power low correspond to n increasing with frequency and here, as in majority of disordered solids, n value in the high frequency region is between 0.5 and 1.0. Literature data [31][32][33] have shown that the conductivity mechanism in any material could be understood from the temperature dependent behaviour of n. To comprehend the electrical conduction mechanism in the materials, different models have been proposed (regarding frequency and temperature dependence of the exponent n). If the exponent n depends on the frequency but it is temperature independent, the quantum mechanical tunnelling (QMT) model can be proposed where the conductivity is believed to be due to the phonon-assisted tunnelling between defect states.…”

“…In this model, tunnelling of polarons is the dominant mechanism; the large polaron wells at two sites overlap and reduce the polaron-hopping energy. Finally, if the exponent n decreases with temperature, the correlated barrier hopping (CBH) model can be suggested, according to which the charge transport occurs between localized states due to the hopping over the potential barriers [32].…”