FATIGUE BEHAVIORS OF Bi_3.25La_0.75Ti₃O₁₂/Pb(Zr_0.52Ti_0.48)O₃/ Bi_3.25La_0.75Ti₃O₁₂ TRILAYERED THIN FILMS

ABSTRACT

The polarization fatigue behaviors of ferroelectric Bi_3.25La_0.75Ti₃O₁₂ (BLT)/Pb(Zr_0.52Ti_0.48)O₃ (PZT)/Bi_3.25La_0.75Ti₃O₁₂ (BLT) trilayered thin films deposited on Pt-coated silicon substrates are investigated. The saturated polarization P _s and remnant polarization P _r of the trilayered structures are enhanced with respect to BLT films, upon insertion of PZT layer. The trilayered structure is almost fatigue-free upon 10⁹switching cycles under an electric field of 350 kV/cm, while a more serious fatigue effect under a lower electric field is observed. Furthermore, the low-temperature fatigue-resistance performance of the trilayered structure is worse than that of BLT films. Referring to the defect chemistry associated with the fatigue behaviors in perovskite ferroelectrics, it is argued that the fatigue effect of the trilayered structure is ascribed to the accelerated penetration of oxygen vacancies from PZT layer into BLT layers.

Keywords:

• Ferroelectric
• fatigue
• BLT
• PZT
• thin film

PACS numbers:

• 62.20.Mk
• 77.80.-e; 77

ACKNOWLEDGMENT

This work was supported by the National Nature Science Foundation of China (10474039, 50332020 and 10021001), the National Key Projects for Basic Research of China (2002CB613303).