Engineered Interfaces of Artificial Perovskite Oxide Superlattices via Nanosheet Deposition Process

Combining different materials into desired superlattice structures can produce new electronic states at the interface and the opportunity to create artificial materials with novel properties. Here we introduce a new, rather unexpected, and yet simple way to such a superlattice assembly of perovskite oxides: in the Dion−Jacobson phase, a model system of layered perovskites, high-quality bicolor perovskite superlattices (LaNb2O7) nL (Ca2Nb3O10) nC are successfully fabricated by a layer-by-layer assembly using two different perovskite nanosheets (LaNb2O7 and Ca2Nb3O10) as a building block. The artificially fabricated (LaNb2O7/Ca2Nb3O10) superlattices are structurally unique, which is not feasible to create in the bulk form. By such an artificial structuring, we found that (LaNb2O7/Ca2Nb3O10) superlattices possess a new form of interface coupling, which gives rise to ferroelectricity.