Effect of the orientation polarization and texturing on nano-mechanical and piezoelectric properties of PZT (52/48) films

Ferroelectric (piezoelectric) Pb (Zr 0.52 Ti 0.48 ) O 3 (PZT) films were synthesized using an aerosol-assisted chemical vapor deposition technique on (111) Pt/Ti/SiO 2 /Si substrates. The optimum deposition temperature was 350 °C, followed by annealing at 650 °C for 1 h. Tetragonal perovskite phase and preferred orientation {0 0 1} in the PZT films were determined by two-dimensional grazing incidence diffraction using synchrotron X-ray radiation and nano-beam electron diffraction (NBED). The PZT film grains’ texture, represented by inverse pole representation, correlates with (0 0 1) and (1 1 1) orientations with approximate XRD peak distribution width of Ω ≈ 35°. The elastic-to-plastic transition of the piezoelectric-based structural deformation of the PZT films is represented by the pop-in, which marks the limit in the elastic behavior at the yield stress for which the material starts exhibiting permanent deformation, with the yield point being Y = 2.5 ± 0.7 GPa for the Pb (Zr 0.52 Ti 0.48 ) O 3 film. The hardness ( H = 7.5 ± 0.16 GPa), elastic modulus ( E = 126 ± 3 GPa), and scratching were evaluated at the nanoscale, using a nanoindentation technique. No delamination or cracks were observed near the residual scratching stage. The switching of piezoelectric domains and domain polarization process, as a function of films’ texture, in the representative Pb (Zr 0.52 Ti 0.48 ) O 3 films, were studied using Piezoresponse Force Microscopy (PFM). The values of the saturation polarization, remnant polarization, coercive field, and piezoelectric constant were P s = 45 μC/cm 2 , P r =30 μC/cm 2 , E c = 22 kV/cm, and d 33 = 137 pm/V, respectively. The local piezoelectric hysteresis loops and film nanostructure correlate with the polarization orientation.