Piezoelectric bending response and switching behavior of ferroelectric/paraelectric bilayers

摘要

We consider the dynamic piezoelectric bending response and switching behavior of ferroelectric/paraelectric bilayers due to an applied electric field. A thermodynamic model is developed, in which the stresses due to the lattice mismatch and ferroelectric phase transformation are inhomogeneous. The polarization, radius of curvature, and relative vertical displacement due to the bending are calculated and analyzed as a function of the ratio of the thicknesses of the two layers. The bending response is found to be very large, and is highly adjustable by varying the relative thicknesses of the two layers. Our results show ferroelectric/paraelectric bilayers may have very good potential for applications as transducers, sensors and actuators.