Formation identification of Y2BaCuO5 and BaCeO3 in MOCVD-processed YBCO films with Ce doping

Abstract

The influence of nanosized secondary particles, such as those produced via rare-earth doping for example, on magnetic-field-induced flux motion in YBa2Cu3O7-delta (YBCO)-coated conductors has been investigated. In this study, we investigated the influence of Ce doping on nanosized secondary phase formation in YBCO films. Ce-doped YBCO films on single SrTiO3 crystals were prepared viametal-organic chemical vapor deposition (MOCVD). For the first time, a Y2BaCuO5 (Y211) secondary phase was observed in the Ce-doped YBCO film, while the pure YBCO film contained only a Y2O3 secondary phase. As Ce doping concentration increased to 3 wt%, a BaCeO3 secondary phase developed. This was due to the low solubility limit of Ce for Y in the MOCVD YBCO film. Additionally, outgrowths on the Ce-doped YBCO film surfaces and defect structures, such as a-axis grains, were examined.