Stacking faults in YBa_2Cu_3O_(7-x): Measurement using x-ray diffraction and effects on critical current

摘要

The density n of stacking faults (SFs) in epitaxial YBa_2Cu_3O_(7-x) (Y123) films, consisting of extra CuO planes, is measured by fitting x-ray diffraction patterns using a random stacking model. The SF density is n=0.068 nm~(-1) in films grown by metal-organic deposition on textured templates and optimized for high I_c. The presence of SF is correlated with pinning of magnetic field (H) applied in the Y123 ab plane. SF can be nearly eliminated by a high temperature anneal, or by adding excess Dy, resulting in I_c which is nearly independent of the orientation of H.