Effect of epitaxial strain on the properties of short-period BaTiO3/PbTiO3 superlattice from first-principles calculations

Tetragonal ferroelectric/ferroelectric BaTiO3/PbTiO3 superlattice under epitaxial compressive strain is investigated from first principles. Our calculated results reveal that the appropriate epitaxial compressive strain can greatly enhance the piezoelectricity for the ferroelectric superlattice. The unexpected epitaxial strain-induced enhancement of piezoelectricity is driven by the drastic enhancement of atomic displacements along the c axis.