Nanostripes in superconducting REBa 2 Cu 3 O 7 -δ superconductors: robust vortex pinning sites

Abstract

We report a naturally grown stripe structure with a nanometer scale wavelength in REBa 2 Cu 3 O 7-δ (RE = Sm and Eu) superconductors investigated with scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). Such a periodic array was unveiled owning to the 3 dimensionally spatial oscillation of RE and Ba around the stoichiometric ratio. The study displayed that novel nanostripes function as robust pinning sites and effectively enhance the peak effect and the irreversibility line at 77K. This illustrates an approach to fabricate high performance REBa 2 Cu 3 O 7-δ superconductors for application in liquid nitrogen temperature.