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

The pyroelectric coefficient and susceptibility of a ferroelectric bilayer with an antiferroelectric material coupling are investigated using the transverse Ising model within the effective field theory with a probability distribution technique. The effects of the magnitude interfacial coupling and the transverse field on the pyroelectric coefficient and susceptibility of the bilayer are discussed. It is shown that there exists a negative peak of pyroelectric coefficient which has not been found in the bilayer or the superlattice with ferroelectric interfacial coupling. We find that the pyroelectric coefficient and the susceptibility increase with the decrease of the magnitude of the interfacial coupling before the phase transition. We also find that a large transverse field and weak interfacial coupling can lead to the disappearance of some of the peaks of the pyroelectric coefficient and susceptibility of the bilayer.