Phase diagrams of BaTiO3/SrTiO3 superlattices from first principles

A first-principles-based technique is used to determine the temperature versus misfit strain phase diagram of epitaxially grown (001) BaTiO3/SrTiO3 superlattices of different periods. Short superlattices exhibit a phase diagram that resemble that of (001) BaTiO3 thin films under short-circuit-like conditions. On the other hand, original domain patterns with unusual atomistic features occurred in the longer superlattices. The reason behind such a dramatic difference between short and longer superlattices is discussed.