AC conduction of Ba1−xCaxTiO3 and BZT-BCTx

Ba_1−xCa_xTiO₃ (BCTx), (x =0.0–0.3) and Ba_0.8Zr_0.2TiO₃-Ba_1−xCa_xTiO₃ (BZT-BCTx), (x=0.15–0.35) were fabricated by the solid state reaction method. Phase structure of the material samples was identified by X-ray diffraction. The impedance versus frequency in a range of 100 Hz to 2.5 MHz was measured for all the samples at room temperature. AC conductivity versus frequency of the BCTx and BZT-BCTx was evaluated and fitted by using the extended Universal Dielectric Response (UDR) equations. The fitting results were discussed in detail and shown that the localized reorientation polarization-based mechanism is most contributed in BCTx matrial samples. Basically both two the hopping polaron and polarization mechanisms play roles in BZT-BCTx material samples. In contrary the short-range polaron hopping is dominated in ac conductivity of BZT-BCTx material samples in low frequency range.