Domain structure and dielectric properties in nanocomposite ferroelectric thin layers with spherical dielectric inclusions

摘要

The phase field model was used to simulate the domain structure and polarization versus applied field hysteresis curves of a composite layer consisting of a ferroelectric matrix and spherical dielectric inclusions. Simulation results demonstrate that the introduction of dielectric inclusions into the ferroelectric matrix can lead to the stabilization of the polydomain structure in a wide range of applied fields. As a result a significant increase in susceptibility can be obtained due to the composite structure formation, which causes the addition of an extrinsic contribution into susceptibility. The composite structure can produce a number of different partially switched (partially poled) states with different values of the remnant polarization that are stable in wide ranges of the applied field producing a close to linear dielectric response with high susceptibility.