Interface control of ferroelectricity in LaNiO3-BaTiO3 superlattices

Abstract

LaNiO3-BaTiO3 superlattices with different types of interfaces are studied from first-principles density-functional theory. It is revealed that the ferroelectricity in the superlattice with (NiO2)−/(BaO)0 interfaces is enhanced from that of the superlattice with (LaO)+/(TiO2)0 interfaces. The origin lies at the polar discontinuity at the interface, which makes the holes localized within the (NiO2)−/(BaO)0 interface, but drives a penetration of electrons into BaTiO3 component near (LaO)+/(TiO2)0 interface. Our calculations demonstrate an effective avenue to the robust ferroelectricity in BaTiO3 ultrathin films.