We studied the phase transitions, domain morphologies, and polarizations in BaTiO3/SrTiO3 superlattices grown on SrTiO3 substrates. Using the phase field approach, we discovered the remarkable influence of film/substrate interfacial coherency on the ferroelectricity of the SrTiO3 layers within a superlattice: it is an orthorhombic ferroelectric for an incoherent interface while it exhibits only induced polarization by the adjacent BaTiO3 layers for a coherent interface. We presented the domain morphologies within individual BaTiO3 and SrTiO3 layers which have different ferroelectric symmetries. The results are compared to ultraviolet Raman spectroscopy and variable temperature x-ray diffraction measurements.
Li, Y. L.; Hu, S. Y.; Tenne, Dmitri; Soukiassian, A.; Schlom, D. G.; Xi, X. X.; and Choi, K. J.. (2007). "Interfacial Coherency and Ferroelectricity of BaTiO3/SrTiO3 Superlattice Films". Applied Physics Letters, 91(25), 252904-1 - 252904-3. http://dx.doi.org/10.1063/1.2823608