New non-fatigue ferroelectric thin films of barium bismuth tantalate

New non-fatigue ferroelectric thin films of barium bismuth tantalate (BaBi2Ta2O9) were synthesized in this work. These films were prepared on Pt/Ti/SiO2/Si substrates by the metalorganic decomposition method. As-deposited films were amorphous, and became well-crystallized after annealing at 700 degrees C. The annealed films exhibited fairly smooth surface and small grain size (around 10 nm). The measured dielectric constant and dissipation factor of BaBi2Ta2O9 films at 10 kHz were 97.7 and 0.0257, respectively. The polarization-electric field hysteresis loops revealed the ferroelectric characteristics of BaBi2Ta2O9 films. Furthermore, the fatigue test indicated that these films hardly degraded in the polarization after 10(9) switching cycles. Because of its ferroelectric properties and excellent fatigue resistance, BaBi2Ta2O9 has great potential in becoming a new candidate material for the applications of ferroelectric random access memories. (C) 1999 Elsevier Science B.V. All rights reserved.