Dielectric Property Of Sol-gel Derived Ba_xSr_1-x TiO₃(BST) Film

This paper introduces in detail the future application of BaxSr1-xTiO3(BST) thin film and the main problems of this material and the method to solve these problems. To enhance the dielectric constant and at the same time low the loss tangent, Polycrystalline BaTiOs/SrTiOs multilayered thin films have been prepared on Pt/Ti/SiO2/Si substrates by a sol-gel processing. The X-ray diffraction (XRD) patterns and Auger electron spectroscopy (AES) indicate that the multilayered thin films were formed. The dielectric constant of the multilayered films was significantly enhanced and the dielectric loss was almost the same as that of the uniform BaTiO3 and SrTiO3 thin films. A dielectric constant of 660 at 1kHz was observed for a stacking periodicity of 66nm at room temperature and the corresponding dielectric loss was maintained below 0.05. The study indicates that there are some differences between the multilayered films and the uniform films in the dielectric constant-frequency relation and capacitance-voltage characteristics. The report also analyses the mechanism of dielectric enhancement of the multilayered thin films prepared by the sol-gel process.Graduate Student Xu RunDirected by Shen Mingrong...