Size-dependent electromechanical response and ferroelectric behavior of engineered morphotropic phase boundary PbZr1−Ti O3 nano-heterostructures

Abstract

Abstract An enhancement of electromechanical performance in ferroelectric materials commonly requires a delicate control of compositions to the proximity of morphotropic phase boundary. Here, we demonstrate an alternative design strategy for enhanced electromechanical responses by engineering ferroelectric PbZr 1 − x Ti x O 3 nano-heterostructures, where the overall composition is near the morphotropic phase boundary yet compositions of constitutive layers are far from the boundary. Effects of layer thickness on the ferroelectric and piezoelectric properties of such engineered heterostructures are investigated by using phase field model. The obtained results reveal an unusual behaviors of domain structures according to the reduction of film thickness. Importantly, piezoelectricity can be enhanced significantly due to the strong interaction among polarization phases near the interface when the layer thickness reduces. In addition, the coercive electric field also decreases, which facilitates the polarization switching. Ultimately, this study paves a route for artificial heterostructure design to enhance electrical and electromechanical performances.