Intrinsic Piezoelectricity of PZT

An unresolved issue in the commonly used Pb(Zr1–xTix)O3 (PZT) ceramics is understanding the intrinsic piezoelectric behaviors of the crystal around the morphotropic phase boundary (MPB). Here, we demonstrate an approach to grow c-axis-oriented tetragonal PZT around the 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 46.3 ± 4.4 pm/V and 88.7 ± 4.6 μC/cm2, respectively, for x = 0.47 close to the MPB. These values align well with the predicted values of d33 = 50–55 pC/N and Ps = 79 μC/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 the 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.