Pyroelectric coefficient and dielectric susceptibility of a ferroelectric bilayer with an antiferroelectric interfacial coupling

The pyroelectric coefficient and dielectric susceptibility of a ferroelectric bilayer with an antiferroelectric interfacial coupling are investigated by the transverse Ising model within the framework of the mean-field theory. The effects of long-range interaction, surface, interface and transverse field on the pyroelectric coefficient and dielectric susceptibility of the bilayer are presented. It is shown that there exists a negative peak of the pyroelectric coefficient, which has not been found in bilayers or superlattices with ferroelectric interfacial coupling. We find that the pyroelectric coefficient and the dielectric susceptibility increase with the decrease of the magnitude of the long-range interaction and the interfacial coupling before the phase transition. We also find that the strong long-range interaction, the large transverse field and weak interfacial coupling can lead to the disappearance of some peaks of the pyroelectric coefficient and dielectric susceptibility of the bilayer. The phase transition temperature increases with the increase of the strength of the long-range interaction, which is similar to the results in multiple layers or superlattices with ferroelectric interfacial coupling.