Strain-coupled ferroelectric polarization in BaTiO3-CaTiO3 superlattices

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3153512· OSTI ID:979191

Seo, Sung Seok A ^[1]; Lee, Ho Nyung ^[1]

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1. 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 Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 979191
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 23 Vol. 94; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIELECTRIC MATERIALS
ELECTROSTATICS
POLARIZATION
STRAINS
SUPERLATTICES
THICKNESS