Anomalous Polarization Switching Characteristics In A Ferroelectric Heterostructure

The polarization switching characteristics of a ferroelectric heterostructure consists of two different ferroelectric films with surface transition layer within each film and a ferroelectric interfacial coupling at the interface between the two films according to Landau-Devonshire theory in combination with Landau-Khalatnikov dynamic equation, as first presented in this work. A parameter is introduced to describe the differences of physical characteristics between the two constituent films of the ferroelectric heterostructure. We focus on studying the combined influence of parameter and ferroelectric interfacial coupling on the polarization switching behavior of the system. The evolution with time of polarization, hysteresis loop, and equilibrium action of the ferroelectric coupling phi and parameter are obtained by numerical calculations. The results exhibit some anomalous phenomena.