ORIENTATION DEPENDENCE OF FERROELECTRIC AND DIELECTRIC PROPERTIES IN CaBi₄Ti₄O₁₅ THIN FILMS

ABSTRACT

Ferroelectric CaBi₄Ti₄O₁₅ (CBTi) thin films with random orientation and high c-axis orientation were prepared on a Pt(111)/Ti/SiO₂/Si(100) substrate by a chemical solution deposition method. We observed a strong dependence of ferroelectric and dielectric properties on the film orientation. The CBTi thin film with random orientation exhibited remnant polarization (2P _r ) of 54 μ C/cm² at an applied electric field of 250 kV/cm and dielectric constant (ε) of 412 at a frequency of 1 kHz. The values of 2P _r and ε were larger than those observed in the CBTi thin film with high c-axis orientation. In addition, the randomly oriented thin film showed lower leakage current density than the highly c-axis-oriented thin film.

Keywords:

• CaBi₄Ti₄O₁₅
• orientation
• ferroelectric property
• dielectric property

ACKNOWLEDGMENTS

This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007-412-J00901).