Pt/BST/Al_2O_3 and Pt/BST/Ce O_2/Al_2O_3 interdigital capacitors were fabricated on the Al_2O_3(1102) substrates, in which Ce O_2 buffer layer and Ba_(0.6)Sr_(0.4)TiO_3(BST) film were prepared by magnetron sputtering and pulsed laser deposition, respectively. Impacts of Ce O_2 buffer layer on structure, surface morphology and dielectric properties of the deposited BST thin film were investigated using X-ray diffraction system, atomic force microscope and LCR meter, respectively. It is found that BST film gr...