Composition-driven phase coexistence and functional properties of the (1-x)BZT-(x)BCT ceramics near the phase convergence region

Abstract

The concept of composition-induced phase transformation in Lead Zirconate Titanate (PZT) at the Morphotropic Phase Boundary (MPB) has been employed to improve functional properties of the (1-x)BZT-(x)BCT ceramic. However, it was observed that the phase diagram of the (1-x)BZT-(x)BCT ceramic is different to the PZT. As a result, the nature of the superior functional properties found in (1-x)BZT-(x)BCT ceramic is unlike PZT and still unclear so far. In this work, functional properties; dielectric, ferroelectric, energy storage, and piezoelectric properties, of the (1-x)BZT-(x)BCT ceramics where x = 0.3 mol% to 0.6 mol% were evaluated at room temperature in comparison to the identification of phase coexistence using synchrotron x-ray powder diffraction (SXPD). This work found that changes of BCT content had a strong impact on the observed coexisting phases and functional properties. Moreover, the composition that showed the highest piezoelectric properties did not present the largest of saturation polarization. This implies that the functional properties of the (1-x)BZT-(x)BCT ceramics are not dependent on the presence of polarizations under the application of electric field. The contribution of non-180° domain switching also plays a vital role, especially in the piezoelectric properties. These findings would help to extend our knowledge of the nature of the (1-x)BZT-(x)BCT ceramic.