Improved flux‐pinning properties of REBa₂Cu₃O_7–z films by low‐level Co doping

Abstract

Biaxially textured REBa2Cu3–xCoxO7–z (RE = Gd,Y) films were prepared on (00l) LaAlO3 substrate using self‐developed fluorine‐free chemical solution deposition (CSD) approach. The in‐field Jc values are significantly improved for REBa2Cu3–xCoxO7–z films through low‐level Co doping. Co‐doped GdBa2Cu3O7–z film shows the highest Jc values at higher temperatures and fields, whereas the Jc values of Co‐doped YBa2Cu3O7–z film surpass that of other films at lower temperatures and fields. In addition, the volume pinning force densities of films with Co doping have been distinctly enhanced in the applied fields, indicating improved flux‐pinning properties. The possible reasons are discussed in detail.

Influence of chemical doping on flux pinning of GdBa2Cu3O7−z films

“…Hence, it is necessary to investigate the properties of BZO-doped REBCO films made by our newly developed FF-PA-MOD method. On the other hand, our previous study revealed the enhancement of the flux pinning properties in low-level Co-doped REBCO films [23-25]. Different from the BZO doping, the lattice deformation and the decrease in hole-carrier concentration introduced by Co doping to CuO chain are suggested to be the effective pinning centres.…”