Modified process engineering at morphotropic phase boundary for enhanced grain size and piezoelectric response in lead free BZT-BCT

We perform systematic investigation on (1-x)Ba(Zr_0.20Ti_0.80)O₃-x(Ba_0.70Ca_0.30)TiO₃ ceramics prepared by solid state reaction technique. We thoroughly investigate the effect of synthesis procedure on crystal structure, microstructure, dielectric, ferroelectric, and piezoelectric properties. Room temperature X-Ray diffraction (XRD) patterns reveal that the as synthesized samples crystallize with desired perovskite phase. Scanning electron microscopy depicts that the grain size shows significant enhancement in size. Large grains having size ~ 36 μm were observed in 50(BZT-BCT) composition prepared using modified synthesis route. Dielectric analysis depicts that the Curie temperature ‘T_c’ and diffusive coefficient ‘γ’ are considerably affected by the synthesis process. Ferroelectric studies show the well saturated loops at 30 kV/cm, and observed maximum values of remnant polarization (P_r), saturation polarization (P_s) and low values of coercive field (E_c) ~ 12.39 μC/cm², 22.67 μC/cm² and 3.05 kV/cm, respectively for 50(BZT-BCT) composition. Excellent piezoelectric properties (d₃₃ ~ 520 pC/N and k_p ~ 57.5%) were observed in 50(BZT-BCT) ceramic. The present manuscript highlights the various parameters affected the synthesis process. The results show that the modified synthesis route enhanced the properties of the ceramic and are promising candidates for lead-free piezoelectric applications.