Electrical and Ferroelectric Properties of Strontium Doped Lead-Free BCZT Ceramics

Herein, we synthesized Ba0.9-xCa0.1SrxTi0.8Zr0.2O3 (x = 0.05, 0.1, 0.15, 0.2) ceramic samples by employing a solid-state reaction technique. The variation of dielectric constant is studied concerning temperature in the range 1 kHz to 1 MHz frequency. Variation of dielectric constant ( epsilon r ) with temperature reveals that charge carrier dispersion pushes the transition temperature towards higher frequency. Impedance analysis reveals that the maximum value of the imaginary part of impedance i.e., Z '' maxima, increases in all samples except for x = 0.05, which shows the opposite behaviour. This behaviour is due to the calcium (Ca2+) substitution at the titanium (Ti4+)-site at low doping concentration of Sr2+ ions. Nyquist plots show the presence of a single semi-circular arc, indicating the contribution of resistance and capacitance through grain boundary. PE hysteresis loops reveal that the values of saturation polarization ( P s ) decrease with increasing Sr-doping, from 10.989 mu C cm-2 to 6.586 mu C cm-2, whereas the remnant polarization ( P r ) shows variable values with increasing Sr-doping.