Structural, dielectric and electrical transport properties of thermal stable (1-x)K0.5Bi0.5TiO3-xBaTiO3 ceramics

Polycrystalline samples of (1-x)K0.5Bi0.5TiO3 - xBaTiO3 [(1-x)KBT - xBT] were synthesized using a solid -state reaction pathway. X-ray diffraction analysis confirmed the presence of a single-phase perovskite structure. To explore relaxation and conduction mechanisms, complex impedance spectroscopy was employed. Reduction in Curie temperature was observed as BT content increased. The grain and grain boundary contributions to relaxation was examined through complex impedance and modulus plots and quantified via fitting experimental data to an equivalent circuit model. Examination of the Complex impedance spectra uncovered the existence of dielectric relaxation characteristic of a non-Debye nature. Furthermore, the activation energy determined suggests commonalities in governing the conduction and relaxation processes in relation to temperature-dependent conductivity and relaxation time. A negative temperature coefficient of resistance behaviour was obtained from the temperature-dependent conductive study. Dielectric spectra revealed that these ceramic capacitors are useful in reduction of signal interference, signal attenuation and impedance matching circuits applications.