Ce掺杂Ba0.6Sr0.4TiO3薄膜表面结构XPS研究

用改进的溶胶-凝胶法制备铈(Ce)掺杂和非掺杂2种钛酸铝钡(Ba_(0.6)Sr_(0.4)TiO_3,BST)薄膜,用X射线光电子能谱(XPS)研究薄膜的表面结构.XPS结果表明,BST薄膜的表面结构由钙钛矿结构和非钙钛矿结构组成,铈掺杂显著地减少了非钙钛矿结构.扫描电镜及原子力显微镜观察表明,掺杂BST薄膜光滑致密无裂纹.电压-电容曲线表明,掺杂BST薄膜的介电性能大幅度提高,在40V外加电压下介电调谐率达60.8%,零偏压下的介电损耗为0.0265.同时,就非钙钛矿结构的成因及Ce掺杂BST薄膜的有关改善机制进行了讨论.

Surface Structures of Ce-Doped Ba0.6Sr0.4TiO3 Films by X-Ray

Cerium (Ce)-doped barium strontium titanate (Ba0.6Sr0.4TiO3, BST) films and undoped BST films have been prepared by an improved Sol-gel method. The surface structures have been studied by X-ray photoelectron spectroscopy (XPS). The result reveals that the surface structures are composed of perovskited structure and non-perovskited structure, and the Ce doping significantly reduces the non-perovskited structure. It is by scanning electron microscope and atomic force microscope shown that the Ce-doped BST films are smooth and compact without crack or shrinkage cavity, which are associated with the formation of the non-perovskited structure. The voltage-capacitance curves demonstrate that the Ce-doped BST films have significant improvement in dielectric properties with a tunability of more than 60.8% at 40 voltage, and a dielectric loss (tand) of 0.0265 at zero bias. The improved mechanism of Ce doping is discussed