The influence of epitaxial strain on the crystal structure and polarization of KNbO3/NaNbO3 (KNO/NNO) superlattice has been quantified using density functional theory based on pseudopotential and plane-wave basis. A sequence of structural phase transitions with changing the in-plane misfit strain has been identified. If the compressive strain is more than -0.8%, tetragonal phase with polarization along  is stable. For the misfit strain between -0.8% and 0.36%, the stable phase is monoclinic while the stable phase becomes orthorhombic with polarization along  when the tensile strain is more than 0.36%. The spontaneous polarization in the orthorhombic phase reaches more than 70 μC/ cm2.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)