Strain-coupled ferroelectric polarization in BaTiO3-CaTiO3 superlattices
- ORNL
We report on growth and ferroelectric (FE) properties of superlattices (SLs) composed of the FE BaTiO{sub 3} and the paraelectric CaTiO{sub 3}. Previous theories have predicted that the polarization in (BaTiO{sub 3})n/(CaTiO{sub 3})n SLs increases as the sublayer thickness (n) increases when the same strain state is maintained. However, our BaTiO{sub 3}/CaTiO{sub 3} SLs show a varying lattice-strain state and systematic reduction in polarization with increasing n while coherently strained SLs with n = 1 and 2 show a FE polarization of ca. 8.5 {micro}C/cm{sup 2}. We suggest that the strain coupling plays a more important role in FE properties than the electrostatic interlayer coupling based on constant dielectric permittivities.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 979191
- Journal Information:
- Applied Physics Letters, Vol. 94, Issue 23; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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