Piezoelectric properties of II-IV/I-V and II-IV/III-III ferroelectric perovskite superlattices

Abstract: The stability of high-symmetry $P4mm$ polar phase in eleven ferroelectric perovskite superlattices with the polar discontinuity is studied from first principles. In most superlattices, this phase exhibits either the ferroelectric or the antiferrodistortive instability, or both of them. The structure of the ground state and, for a number of systems, also of metastable phases in these superlattices is found. The spontaneous polarization and piezoelectric properties of superlattices are calculated. The appearance of high piezoelectric coefficients (up to 150-270 pC/N) in some superlattices is associated with the strain-induced local rearrangement of certain atomic groups in the primitive cell.