Pulsed laser deposition of epitaxial Ba_xSr_1-xTiO₃/YBa₂Cu₃O₇ bilayers on LaAIO₃ substrates

YBa₂Cu₃O₇/Ba_xSr_1-xTiO₃ bilayers were grown epitaxially on LaA10₃ substrates using the pulsed laser deposition method. A microstructural investigation revealed that all compositions of Ba_xSr_1-xTiO₃ investigated from x = 0 to x = 1 showed (001) orientation and epitaxy across the interface as analyzed by Rutherford backscattering spectroscopy channel yields of < 8% for BaTiO₃ on YBa₂Cu₃O₇ films. Dielectric properties including the dielectric constant, k, and the loss tangent, tan δ, were measured as a function of composition, and it was found that the highest k-values (k = 400) existed for the x = 0.72 composition.