The dynamics hysteresis loop and dielectric susceptibility characteristics of a ferroelectric heterostructure

The dynamic properties, including hysteresis loop and dielectric susceptibility, of a ferroelectric heterostructure composed by two different films have been discussed, by means of a Landau–Devonshire theory in combination with Landau–Khalatnikov dynamic equation. The surface transition layer within each component film and a ferroelectric coupling at the interface between two films are taken into account. A parameter is introduced to describe the differences of physical properties between two constituent films. The results show that if the ferroelectric interfacial coupling is large enough, the system will lead to the severe hysteresis phenomenon for hysteresis loop and four peaks of the curve for dielectric susceptibility versus the electric field.