We report a nanoscaled crisscross network in high-quality melt-processed (Sm0.33 Eu0.33 Gd0.33) Ba2 Cu3 O7-δ superconductors investigated with atomic force microscopy (AFM) and transmission electron microscopy. In the ten-micrometer scale, such a net was unveiled as a consequence of crossing annular stripes originating from ordering compositional modulation. The AFM topographic images further displayed that this compositional stripe result in a surface modulation with a few-nanometer wavelength and roughness. The forming mechanism of this compositional stripe and its role as strong δ Tc -type pinning defects were discussed in the context of rare earth Ba oscillation around the stoichiometric ratio and the spatial fluctuation of local Tc values.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)