Europhys. Lett.
Volume 76, Number 1, October 2006
Page(s) 88 - 94
Section Condensed matter: structural, mechanical and thermal properties
Published online 06 September 2006
Europhys. Lett., 76 (1), pp. 88-94 (2006)
DOI: 10.1209/epl/i2005-10604-2

Temperature-dependent fatigue rate in ferroelectric $\chem{Bi_{3.25}La_{0.75}Ti_{3}O_{12}}$ thin films

J.-Y. Hwang1, S.-A. Lee2, S.-Y. Jeong3 and C.-R. Cho4

1  Nano-Surface Technology Research Lab, Korea Basic Science Institute Busan 609-735, Korea
2  Department of Physics, Pusan National University - Busan 609-735, Korea
3  School of Nano-Science and Technology, Pusan National University Busan 609-735, Korea
4  Department of Nanomedical Engineering and PNU-Fraunhofer IGB Joint Research Center, Pusan National University - Miryang 627-706, Korea

received 5 December 2005; accepted in final form 1 August 2006
published online 6 September 2006

Bismuth-layer-structured ferroelectric (BLSF) thin films with a composition of $\chem{Bi_{3.25}La_{0.75}Ti_{3}O_{12}}$ were prepared by an acetic-acid-based sol-gel route. The ferroelectric, dielectric, and fatigue characteristics of the films over a wide temperature range from 300$\un{K}$ to 100$\un{K}$ were analyzed by using a computerized measurement system. The fatigue characteristic of the film was improved with decreasing temperature. This behavior is attributed to the temperature-dependent changes of domain movement (or freezing), diffusivity (or mobility) of charged defects, and their interactions. It was found that the onset of fatigue ($\propto$ $\it {f/T}$) and the fatigue rate ($\propto$ $\it {T}$) were temperature-dependent parameters. The activation energy of the fatigue rate in sol-gel-derived BLT films was about 1.07$\un{eV}$, which coincides with that of oxygen vacancies in perovskite-type materials. We suggest that the fatigue mechanism in the BLT system is mainly due to the behavior (or movement) of oxygen vacancies.

68.60.Dv - Thermal stability; thermal effects.
77.55.+f - Dielectric thin films.
77.80.-e - Ferroelectricity and antiferroelectricity.

© EDP Sciences 2006