Intrinsic piezoelectricity of PZT

An unresolved issue in the commonly used Pb(Zr1-xTix)O3 (PZT) ceramics is understanding the intrinsic piezoelectric behaviors of its crystal around the morphotropic phase boundary (MPB). Here, we demonstrate a novel approach to grow c-axis oriented PZT around MPB on stainless steel SUS430, allowing us to estimate the intrinsic piezoelectric and ferroelectric properties of PZT along its polar axis. The piezoelectric coefficient d33 and spontaneous polarization Ps were found to be 46.4 +- 4.4 pm/V, 88.7+-4.6 uC/cm2, respectively, for x = 0.47 close to MPB. These values align well with the predicted values of d33 = 50 - 55 pC/N and Ps=79 uC/cm2 at room temperature from the first-principles-derived approach. The obtained d33 is 4 times smaller than that of its ceramics, indicating that the large piezoelectric response in the PZT ceramics around MPB is primarily driven by extrinsic effects rather than intrinsic ones. In the technical application of PZT films, achieving a substantial piezoelectric response requires careful consideration of these extrinsic effects.