Synthesis And Properties Of Doped BaTiO₃ Thin Film

BaTiO3 is one of the most traditional ferroelectric materials, which was researched since the middle of the last century. Generally it has high dielectric constant, excellent ferroelectric, piezoelectric, pyroelectric and photoelectric properties. So it was often applied in nonvolatile memories, dynamic random access memories, pyroelectric detectors and electro-optic devices and so on. And it attracted a lot interests. However, there was still some difficult in prepare the high quality BaTiO3 thin film. The properties of the thin films deposited by present methods were often poor, for example, the dielectric constant was usually significantly lower and hysteresis loops were often absent. Accordingly, the purpose of our research in this paper is to improve the deposition process and the properties of BaTiO3 thin film.Doping with little amount of Fe and Co by sol-gel method, we successfully improved the properties of BaTiO3 thin film, and the details are as follows:(1) The traditional sol-gel method was improved, the precursor of Fe and Co doped BaTiO3 thin films were prepared respectively, the Fe doped and Co doped BaTiO3 thin films were successfully deposited on Si and LNO substrates respectively. The pulsed laser deposition was also studied in preparing BaTiO3 thin films, and the properties of films deposited by PLD were also researched.(2) The X-Ray Diffraction was used to study the microstructure of the BaTiO3 thin films, which were prepared in different conditions, such as in low annealing temperature, doping some lactic acid in the BaTiO3 precursor, on the different substrates (Si and LNO), and with different doping (Fe and Co); The Atomic Force Microscope was used to research the surface of the BaTiO3 thin films.(3) The dielectric and ferroelectric properties of doped BaTiO3 thin films were studied, we found that Fe could considerablely improve the ferroelectric properties of BaTiO3 thin film, which could increase the Pr to 14.9μC/cm2 and repress the leakage current of BaTiO3 thin film. The Raman spectroscopy, Reflectance and Magnetic property were also studied.