Temperature-dependent fatigue rate in ferroelectric thin filmsJ.-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 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 to 100 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 ( ) and the fatigue rate ( ) were temperature-dependent parameters. The activation energy of the fatigue rate in sol-gel-derived BLT films was about 1.07, 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