Epitaxial Ba1-xSrxTiO3(BST)/YBa 2Cu3O7-x heterostructures with superior electrical and dielectric properties have been fabricated by plasma-enhanced metalorganic chemical vapor deposition (PE-MOCVD). Data of x-ray diffraction and high resolution transmission electron microscopy showed that 〈100〉 oriented Ba1-xSrxTiO3 layers were epitaxially deposited on epitaxial (001) YBa2Cu3O7-x layers. The leakage current density through the Ba1-xSr xTiO3 films was about 10-7 A/cm2 at 2 V (about 2×105 V/cm) operation. Moreover, the results of capacitance-temperature measurements showed that the PE-MOCVD Ba 1-xSrxTiO3 films had Curie temperatures of about 30°C and a peak dielectric constant of 600 at zero bias voltage. The Rutherford backscattering spectrometry and x-ray diffraction results showed that the BST film composition was controlled between Ba0.75Sr 0.25TiO3 and Ba0.8Sr0.2TiO 3. The structural and electrical properties of the Ba 1-xSrxTiO3/YBa2Cu3O 7-x heterostructure indicated that conductive oxide materials with close lattice to Ba1-xSrxTiO3 can be good candidates for the bottom electrode.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)