Investigation on the electrical characteristics of sol-gel derived Pb_1.05(Zr_0.53Ti_0.47)O₃ thin films

Abstract

Lead zirconate titanate (PZT) thin films with composition Zr/Ti ∼ 0.53/0.47 were deposited by the sol-gel technique. The films were characterized in terms of its polarization relaxation, fatigue and imprint characteristics. We have found that the polarization relaxation is due to the presence of a depolarization field which increases dramatically with the rise in temperature. Improved fatigue performance was observed when the film was fatigued with higher frequency. The direction of imprint depends on the state of polarization. With the increase in net polarization, the trapped charge density at the film-electrode interface increases which leads to imprint characteristics. Also the imprint increases considerably with the rise in temperature. Finally, we have made an attempt to correlate simultaneously fatigue, polarization relaxation, and imprint characteristics with the presence of mobile charge defects (viz. V_o) and defect dipoles (viz. V_Pb – V_o) in the film.

Key Words:

• Sol-gel
• Thin films
• PZT
• Retention
• Imprint
• Fatigue