Study of Ca doping on A- site on the structural and physical properties of BLTMNZ ceramics

The ferroelectric Ca doped (Ba_0.9575La_0.04X_0.0025) (Ti_0.815Mn_0.0025Nb_0.0025Zr_0.18)_0.99O₃ was prepared by a high-temperature solid state reaction technique. For the understanding of the electrical and dielectric property, the relation between the crystal structures, electrical transition and ferroelectric transitions with increasing temperature (-160 to 35°C) have been analyzed. X-ray diffraction analysis of the powders suggests the formation of a single-phase material with monoclinic structure. Capacitance and tan δ of the specimens were measured in the temperature range from -160 to 35°Cat frequencies 1 kHz - 1 MHz. Detailed studies of dielectric and electrical properties indicate that the Curie temperature shifted to higher temperature with the increase in frequency. Moreover, the dielectric maxima dropped down rapidly initially and the dielectric peaks became extremely broad. The AC conductivity increases with increase in frequency. The low value of activation energy obtained for the ceramic samples could be attributed to the influence of electronic contribution to the conductivity.