Nanostripes in GdBa2Cu3Ox high-Tc superconductors

High-Tc superconductors with light rare earth (LRE) elements instead of Y exhibit nanoscale stripe structures on the surface as observed by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) scans. Within the GdBa2Cu3Ox (GdBCO) system exhibiting relatively high critical current densities, nanoclusters arranged in a stripe-like fashion are observed in undoped material, while adding of nanoparticles (ZnO2, ZrO2) leads to the formation of nanostripes as observed in other LRE superconductors. The nanostripes in doped GdBCO exhibit periodicties between 20 and 50 nm and corresponding step heights of 0.3-0.8 nm. Using polarized light microscopy and electron backscatter diffraction (EBSD) analysis, we determined the direction of the nanostripes with respect to the known twin structure