Eu0.6Sr0·4BiO3 buffer layer: A simple but practical route for improving flux pinning in YBa2Cu3O7-x films

• Published in: Journal of alloys and compounds Vol. 815; p. 1
• Main Authors: Zhang, Xin, Xia, Yudong, Pan, Xifeng, Liu, Ming, Cheng, C.H., Zhao, Yong
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 30.01.2020; Elsevier BV
• Subjects: 2G tapes; Buffer layer; Buffer layers; Composite structures; Conductors; Eu0.6Sr0·4BiO3; Flux pinning; Heat treatment; Hysteresis loops; Magnetic fields; Magnetism; Nanoparticles; Organic chemistry; PA-CSD; Self-assembly; Substrates; Thin films; YBCO; YBCO superconductors; Buffer layer; Eu0.6Sr0·4BiO3; YBCO; PA-CSD; 2G tapes
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.152291

In this paper, a Eu0.6Sr0·4BiO3 (ESBO) film with self-assembled SrO2 nanodots was fabricated on a (00l) LaAlO3 (LAO) substrate by a self-developed polymer-assisted chemical solution deposition (PA-CSD) process. A highly epitaxial 450 nm YBa2Cu3O7−x (YBCO) thin film was successfully fabricated on the ESBO/LAO. The YBCO films and buffers were studied with XRD, ESEM, TEM and M − H hysteresis loop analysis, and it was found that the ESBO film can be thought of as a monolithic two-phase composite structure with self-assembled SrO2 nanoparticles, which were formed on the ESBO surface after heat treatment. The YBCO epitaxial coating on the ESBO exhibited a very robust dependence of Jc on the magnetic field. Cross-sectional TEM analysis confirmed that the SrO2 surface nanoparticles caused defects in the YBCO film, resulting in a strong pinning effect on the flux vortex line. The YBCO film grown on the ESBO/LAO produced an approximately 40% increase in Jc compared with that of the control YBCO sample at a low applied magnetic field. Our results illustrate the effectiveness of the simple and low-cost route for achieving high-performance YBCO-coated conductors based on a multifunctional ESBO buffer layer. •Bi-epitaxial Eu0.6Sr0·4BiO3 film with self-assembled SrO2 nanoparticles was fabricated on a (00l) LaAlO3 substrate.•The used method is a newly self-developed polymer-assisted chemical solution deposition.•YBCO epitaxial coating on the Eu0.6Sr0·4BiO3 film exhibits a more robust dependence of Jc on magnetic field.