Compositionally graded epitaxial barium strontium titanate thin films derived from pulsed laser deposition

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 2theta peak at 45degrees 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 2 muC cm(-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 degreesC. All these results can be ascribed to the epitaxial and graded structure of BST thin films. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 20]