Ferroelectric and Piezoelectric properties of (111) oriented lanthanum modified lead zirconate titanate film

Lanthanum modified lead zirconate titanate (PLZT) thick film with molecular formula of Pb0.92La0.08 (Zr0.52Ti0.48)(0.98)O-3 was grown preferentially along (111) direction on Pt/SiO2/Si (platinum/silicon oxide/silicon) substrate by spin coating of chemical solution. The directional growth of the film was facilitated by platinum (Pt) (111) template and rapid thermal annealing. X-ray diffraction pattern and atomic force microscopy revealed the preferential growth of the PLZT film. The film was characterized for ferroelectric and detailed piezoelectric properties in a parallel plate capacitor (metal-PLZT-metal) configuration. Ferroelectric characterization of the film showed saturated hysteresis loop with remanent polarization and coercive electric field values of 10.14 mu C/cm(2) and 42 kV/cm, respectively, at an applied field of 300 kV/cm. Longitudinal piezoelectric coefficient (d(33, f)) was measured by employing converse piezoelectric effect where electrical charge response and displacement were measured with electrical voltage excitation on the sample electrodes. The effective transverse piezoelectric coefficient (e(31, f)) was derived from charge measurement with an appliedmechanical excitation strain by using the four point bending method. d(33, f) and e(31, f) coefficients of PLZT films were found to be 380 pm/V and -0.831 C/m(2) respectively. (C) 2014 Elsevier B.V. All rights reserved.