Bi4Ti3O12 thin films doped with 3 mol.% niobium were prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. The niobium-doped Bi4Ti3O12 (Nb-BiTiO) films annealed at 700 °C for 30 min in oxygen showed randomly oriented layered perovskite structures and was composed of plate-like and rod-like grains with no crack. The remanent polarization (2Pr) and coercive field (2Ec) of the Nb-BiTiO film annealed at 700 °C were 28 μC/cm2 and 110 kV/cm, respectively. In addition, the film showed good switching endurance under bipolar pulse at least up to 4.5 × 1010 cycles. Substitution of Nb in BiTiO thin films was effective for reducing the oxygen vacancies and generating good ferroelectric properties.
Bibliographical noteFunding Information:
This work was supported by the Korea Research Foundation Grant (KRF-2000-005-Y00070).
- Ferroelectric properties
- Scanning electron microscopy
- X-ray diffraction