1. An integrated circuit device including a substrate supporting a first thin film layered superlattice material layer and an electrode, comprising an interface buffer layer interposed between said thin film layered superlattice material layer and said electrode, said interface buffer layer selected from the group consisting of: simple oxides, not including bismuth, of an A-site or a B-site metal; and second layered superlattice materials different from said first layered superlattice material and containing at least one A-site or B-site metal that is the same as an A-site or B-site metal in said first layered superlattice material.