Antiferroelectric Behavior in SymmetricKNbO3/KTaO3Superlattices

Antiferroelectric behavior is observed in artificially layered $\mathrm{KTaO}{}_3/\mathrm{KNbO}{}_3$ perovskite superlattices. While $\mathrm{KTaO}{}_3$ and $\mathrm{KNbO}{}_3$ are ferroelectric and paraelectric, respectively, the superlattice appears antiferroelectric based on an increase in the dielectric constant with applied dc bias. This dielectric behavior is inconsistent with the nonlinear response for either paraelectric or ferroelectric materials. However, an increase in the dielectric constant with applied electric field is consistent with antiferroelectric behavior. The antiferroelectric ordering appears to be induced by cation modulation imposed by the superlattice.