Effect of Annealing Temperature on Properties of Barium Zirconium Titanate Thin Films Deposited by Sol-Gel Method

Abstract

With inorganic salts as the main raw material, the BaZr_0.2Ti_0.8O₃ thin films were prepared on the Pt/Ti/SiO₂/Si substrates by sol-gel method. The films were annealed at 600, 700, 800, 900, 1000°C for 30 min in oxygen. X-ray diffraction shows that the BZT films start to crystallize at 600°C, but crystallization basically completed at 700°C and the crystal structure of the films belongs to tetragonal phase. Analyzing the morphology by scanning electron microscopy, it was found that the film structure is dense, and with less crack and larger grains when the annealing temperature is 900°C; while above this temperature obvious polarization versus electric voltage (P-V) hysteresis loop was observed in BaZr_0.2Ti_0.8O₃ films. When the annealing temperature is 1000°C the remnant polarization (2P _r) and the coercive field (2E _C) of BaZr_0.2Ti_0.8O₃ films obtained from the hysteresis loop are 1.7 μC/cm² and 6.7 kV/cm, respectively.

Keywords:

• Barium zirconium titanate
• films
• sol-gel
• annealing temperature

Acknowledgments

The research is supported by the Research Foundation of Chongqing University of Science and Technology (Grant No.CK2010Z07), the National Natural Science Foundation of China (Grant No.51102288), Natural Science Foundation of Chongqing, China (Grant No. CSTC2010BB4286 and CSTC2011BA4027), Open Research Fund of State Key Laboratory of Electronic Thin Films and Integrated Devices (UESTC) (KFJJ201104) and the Science and Technology Research Project of Chongqing Education Commission, China (Grant No. KJ121408).