Abstract: In this paper we show that experimentally realizable apparentlypiezoelectric thin-film super-lattices can be created from non-piezoelectricmaterials provided an odd-order (e.g. trilayer) stacking sequence is used. Thesize-dependent mechanism of flexoelectricity, which couples gradients of strainto polarization, allows such a possibility. We present closed-form analyticalexpressions for the response of various thin-film and super-latticeconfigurations. We also clarify some of the subtleties that arise inconsidering interface boundary conditions in the theory of flexoelectricity aswell as the relationship of flexoelectricity to the frequently usedpolarization gradient terms used in modeling ferroelectrics. We find that forcertain (optimum) material combinations and length scales, thin filmsuperlattices yielding apparent piezoelectricity close to 75 % of ferroelectricBarium Titanate may be achievable.
展开▼
