AC conductivity and dielectric studies of (C5H10N)2BiCl5 compound

Abstract

The bis (3-dimethylammonium-1-propyne) pentachlorobismuthate (III) exhibits a structural phase transition at T1 = (337 ± 2 K), which has been characterized by differential scanning calorimetric, X-ray powder analysis, AC conductivity and dielectric measurements. The dielectric dispersion yielded the real and imaginary parts of impedance of (C5H10N)2BiCl5 in the form of a semicircle in a complex plane. Besides, a Cole–Cole plot was observed at frequencies ranging from 209 Hz to 5 MHz, whose result was found to fit the theoretical resistor–capacitor parallel circuit model. The temperature dependence of the electrical conductivity in the different phases follows the Arrhenius law. The frequency-dependent conductivity data were fitted in the modified power law: \( \sigma = {\sigma_{dc}} + {B_1}(T){\omega^{{s_1}}} + {B_2}(T){\omega^{{s_2}}} \). The imaginary part of the permittivity constant is analyzed with the Cole–Cole formalism. With regard to the modulus plot, it can be characterized by full width at half height or in terms of a non-exponential decay function \( \phi (t) = \exp {\left( {\frac{{ - t}}{{{\tau_\sigma }}}} \right)^\beta } \). Besides, the activation energy responsible for relaxation has been evaluated and found to be close the DC conductivity.