A ferroelectric superlattice consisting of two ferroelectric materials is investigated based on the transverse Ising model. We study the effects of long-range coupling interactions on the spontaneous polarization, the Curie temperature, and the dielectric susceptibility of the ferroelectric superlattice. We find that with the increase of the interaction range, the spontaneous polarization as well as the Curie temperature increase, and two peaks in dielectric susceptibility become only one gradually. This indicates that the ferroelectric superlattice tends to form a single artificial material.

• Received 14 September 1999

DOI:https://doi.org/10.1103/PhysRevB.61.14279