Effect of F/Ba ratio of precursor solution on the properties of solution-processed YBCO superconducting films. Issue 11 (1st August 2017)

• Record Type: Journal Article
• Authors: Bian, Weibai; Chen, Yuanqing; Huang, Wenhuang; Zhao, Gaoyang; Nishii, Junji; Kaiju, Hideo; Fujioka, Masaya; Li, Lingwei; Li, Na; Yan, Fuxue
• Is Part Of: Ceramics international. Volume 43:Issue 11(2017)
• Page Start: 8433
• Page End: 8439
• Publication Date: 2017-08-01
• Subjects: YBa2Cu3O7−x -- Low-fluorine solution -- Films -- Superconductivity; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.03.193
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: YBa2 Cu3 O7−x (YBCO) thin films (with thickness of 220–230 nm) and thick films (with thickness of 1.1–1.2 µm) were prepared using low fluorine solutions with different F/Ba ratios (F/Ba=1–4.5). The effect of F/Ba ratio on the properties of the films was systematically investigated. The results showed that films derived from solutions with F/Ba<2, regardless of whether they were thin or thick, showed poor superconductivity due to the formation of BaCO3 intermediate phase. When solutions with F/Ba≥2 were used, the superconductivity of as-prepared YBCO films was related to not only the film thickness, but also the F/Ba ratio in the solution. It was found that, for thick films derived from F/Ba>2 solutions, the formation of BaF2 /BaOF phase was retarded by the decomposition of Ba1−x Yx F2+x (BYF) intermediate phase. We also found that extra fluorine in the solution resulted in a large number of impurities and a-axis grains in the thick films, degrading the film superconductivity. F/Ba=2 was the optimal ratio in the solution to fabricate high-Jc YBCO thick films.