Impact of RE/Ba change on RE2O3 phase and BaZrO3 nanorods at low temperature in REBCO superconducting film

The critical current density (Jc) dependence on an applied magnetic field was studied for a prototype REBCO with Zr doping content coated conductor fabricated by metal-organic chemical vapor deposition (MOCVD).The study revealed that different rare-earth (RE) cations were incorporated into the superconducting film to form RE2O3 and BaZrO3 (BZO).RE2O3 nanoparticles had a stronger pinning effect on magnetic flow along the direction of the a-b plane of films.With the increase of RE content, many RE2O3 nanoparticles effectively inhibited the precipitation of Ba-Cu-O heterophase, and when RE/Ba ≥ 0.65, the increase of coarse Ba-Cu-O phases wrecked the continuity of matrix and crystal quality of films, causing a decrease on Jc (90 • ).After excessive RE elements (RE/Ba = 0.70) were doped in film, RE2O3 phases were changed from granular to lamellar and cut off the continuous growth of BZO along the c-axis, reducing Jc (0 • ) of films.K e y w o r d s : rare-earth barium copper oxide (REBCO), RE2O3, BZO, rare-earth (RE), critical current density (Jc)