Epitaxial Ba0.6Sr0.4TiO3 （BST） thin films were deposited on LaAlO3 （LAO） substrates with the conductive metallic oxide La0.5 Sr0.5CoO3 （LSCO） film as a bottom electrode by pulsed laser deposition （PLD）. X-ray ...Epitaxial Ba0.6Sr0.4TiO3 （BST） thin films were deposited on LaAlO3 （LAO） substrates with the conductive metallic oxide La0.5 Sr0.5CoO3 （LSCO） film as a bottom electrode by pulsed laser deposition （PLD）. X-ray diffraction 0-20 andФ scan showed that the epitaxial relationship of BST/LSCO /LAO was [001] BST// [001] LSCO//[001] LAO. The atomic force microscope （AFM） revealed a smooth and crack-free surface of BST films on LSCO-coated LAO substrate with the average grain size of 120 nm and the RMS of 1.564 nm for BST films. Pt/BST/LSCO capacitor was fabricated to perform Capacitance-Voltage measurement indicating good insulating characteristics. For epitaxial BST film, the dielectric constant and dielectric loss were determined as 471 and 0.03, respectively. The tunabilty was 79.59% and the leakage current was 2.63×10^-7 A/cm^2 under an applied filed of 200 kV/cm. Furthermore, it was found that epitaxial BST （60/40） fdms demonstrate well-behaved ferroelectric properties with the remnate polarization of 6.085μC/cm^2 and the coercive field of 72 kV/cm. The different electric properties from bulk BST （60/40） materials with intrinsic paraelectric characteristic are attributed to the interface effects.展开更多
基金This work was supported by the youth science and technology fund of University of Electronic Science and Technology of China No.L08010301JX0617.
文摘Epitaxial Ba0.6Sr0.4TiO3 （BST） thin films were deposited on LaAlO3 （LAO） substrates with the conductive metallic oxide La0.5 Sr0.5CoO3 （LSCO） film as a bottom electrode by pulsed laser deposition （PLD）. X-ray diffraction 0-20 andФ scan showed that the epitaxial relationship of BST/LSCO /LAO was [001] BST// [001] LSCO//[001] LAO. The atomic force microscope （AFM） revealed a smooth and crack-free surface of BST films on LSCO-coated LAO substrate with the average grain size of 120 nm and the RMS of 1.564 nm for BST films. Pt/BST/LSCO capacitor was fabricated to perform Capacitance-Voltage measurement indicating good insulating characteristics. For epitaxial BST film, the dielectric constant and dielectric loss were determined as 471 and 0.03, respectively. The tunabilty was 79.59% and the leakage current was 2.63×10^-7 A/cm^2 under an applied filed of 200 kV/cm. Furthermore, it was found that epitaxial BST （60/40） fdms demonstrate well-behaved ferroelectric properties with the remnate polarization of 6.085μC/cm^2 and the coercive field of 72 kV/cm. The different electric properties from bulk BST （60/40） materials with intrinsic paraelectric characteristic are attributed to the interface effects.
