摘要
Epitaxial graded barium strontium titanate (BaxSr1−x)TiO3 (x=0.75, 0.8, 0.9, 1.0) thin films were prepared through pulsed laser deposition method on the (La0.7Sr0.3)MnO3 (LSMO)/LaAlO3 (LAO) substrate. XRD analysis indicated the graded film had a broadened 2θ peak at 45° for the (200) peak. The energy dispersive analysis of X-ray (EDAX) showed a gradient change of Ba/Sr composition. P–E loop measurement gave a remnant polarization about 2μCcm−2, and without big up offset observed. A big room temperature dielectric constant as high as 1600 was obtained and has an approximately linear relationship with temperature from room temperature to 130°C. All these results can be ascribed to the epitaxial and graded structure of BST thin films.