Papers by Keyword: Hopping Mechanism

Abstract: Barium titanate (BTO) samples were prepared by nanomilling based solid state reaction method. Dielectric behavior of BTO sample has been investigated by temperature dependent impedance spectroscopy. The impedance analysis of BTO samples confirm that hopping of electrons and defects coexisted in sample and contribution of grain and grain boundary to dielectric behavior is discussed. A single semicircular arc obtained by Nyquist plots whose radius decreased with increase in temperature illustrates the prominent role of grains. The activation energy of defects was calculated from Arrhenius plot. These defects may be due to oxygen vacancies and hopping between Ti⁺⁴ to Ti⁺³ ions.

Abstract: Measurement of the ionic conductivity for the CA-NH4CF3SO3-DMC system was carried out at frequencies of 50 Hz to1 MHz and also at temperatures of 298 K to 313 K. The plot of log σ versus 1000/T shows a linear behavior suggesting that the samples obey the Arrhenius relationship. The electrical relaxation of the system was analyzed using the complex electric modulus M* of the sample with the highest ionic conductivity at various temperatures. The analysis of electrical modulus and dissipation factor (tan δ) shows that charge transport occurs through a hopping mechanism.