Enhancement of the piezoelectric property in PMN-PZT/PZT thin films

0.3Pb(Mg_1/3Nb_2/3)O₃-0.7Pb(Zr_0.52Ti_0.48)O₃/Pb(Zr_0.52Ti_0.48)O₃ (PMN-PZT/PZT) piezoelectric films have been deposited on Pt/Ti/SiO₂/Si substrates via in-situ magnetron sputtering process. The purpose of this work was to investigate heterogeneous interfaces-dependent preferential orientation, micro-morphology, and piezoelectric behaviors of the PMN-PZT/PZT films. Uniform and dense columnar grains are observed by Scanning electron microscope (SEM) analysis as increasing the number of hetero-interfaces. For the film with five heterogeneous interfaces (H5), the superior ferroelectricity (2P_r = 21.6 μC/cm², 2E_c = 60 kV/cm) and dielectricity (ε_r = 1012.1, tanδ = 0.022 at 1 kHz) are obtained, which arises from highly dense columnar grain and the influence of heterogeneous interface strain. Moreover, an excellent piezoelectric constant e₃₁ of 8.2C/m² is achieved in H5 film, which is 3.5 times larger than that of PZT film. It is expected that this study will simulates the design and synthesis of new functional materials, and provides a guidance for actuators device fabrication and applications.