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.
This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Applied Physics Letters, published by American Institute of Physics. Copyright restrictions may apply. DOI: 10.1063/1.2823608
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