Applied Physics Letters · 1990 · 196 citations · 8 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid State PhysicsPerovskite MaterialsSuperconducting Thin FilmsChannelingCrystalline StructurePulsed Laser DepositionTwin BoundariesX-ray Diffraction Analysis
We have grown YBa2Cu3O7−x-PrBa2Cu3O7−y heterostructures with the perovskite a axis normal to the surface of a variety of (001) oriented substrates using the pulsed laser deposition technique. X-ray diffraction studies indicate little or no formation of the traditional c-axis normal orientation usually nucleated on these substrates, while ion channeling, transmission electron microscopy (TEM), and Raman scattering studies reveal a highly ordered crystalline structure similar in quality to that obtained in the best c-axis oriented films. Superconducting transition temperatures, for current transport in the plane of the films, consistently exceed 80 K, but are probably lower than the optimum 92 K transition expected for YBa2Cu3O7−x due to the presence of growth twin boundaries between grains with the c axis oriented along the two substrate directions.
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