Preparation and Characterization of Compositionally Graded Epitaxial Barium Strontium Titanate Thin Films via Scanning Probe Microscopy
Epitaxially graded barium strontium titanate (BaxSr1-x)TiO3 (x = 0.75, 0.8, 0.9, 1.0, abbreviated as BST75, BST80, BST90 and BTO respectively) thin films were fabricated by pulsed laser deposition method on the (La0.7Sr0.3)MnO3 (LSMO)/LaAlO3 (LAO) single crystal substrate. Scanning probe microscopy with a contact mode was used to characterize the temperature dependence of polarization from room temperature to 140°C. Results indicated that the piezo-response signal of the BST graded films had an obvious change with temperature, and that the graded structures had a flatter temperaturedependence of permittivity. Furthermore, the contrasts of the SPM images were lower for the ferroelectric – paraelectric (F-P) phase transition temperatures of BST 75, BST 80, and BST90, but higher for the F-P transition temperature of BTO.
Wei Pan, Jianghong Gong, Chang-Chun Ge and Jing-Feng Li
S. G. Lu et al., "Preparation and Characterization of Compositionally Graded Epitaxial Barium Strontium Titanate Thin Films via Scanning Probe Microscopy", Key Engineering Materials, Vols. 280-283, pp. 1903-1908, 2005