Generating mixed morphology BaZrO3 artificial pinning centers for strong and isotropic pinning in BaZrO3–Y2O3 double-doped YBCO thin films. (7th November 2017)

• Record Type: Journal Article
• Authors: Chen, Shihong; Sebastian, Mary Ann; Gautam, Bibek; Wilt, Jamie; Chen, Yanbin; Sun, Lei; Xing, Zhongwen; Haugan, Timothy; Wu, Judy
• Is Part Of: Superconductor science & technology. Volume 30:Number 12(2017:Dec.)
• Publication Date: 2017-11-07
• Subjects: superconductors -- thin films -- flux pinning -- APCs -- microstructure; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aa902f
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: High concentration artificial pinning centers (APCs), such as BaZrO3 nanorods (BZO 1D APCs) aligned along the c -axis of the high temperature superconductor YBa2 Cu3 O7 (YBCO) can provide strong pinning of magnetic vortices and are desirable for applications in high magnetic fields. Unfortunately, in YBCO films with single-doping (SD) of BZO 1D APCs, a monotonic decreasing superconducting T c and critical current density J c ( H ) with BZO doping has been observed due to strain field overlap at high-concentration perfectly c -axis aligned BZO 1D APCs. In order to resolve this issue, double-doping (DD) of 2–6 vol% BZO 1D APCs and 3.0 vol% Y2 O3 nanoparticles (Y2 O3 -NPs) in YBCO films has been explored to promote BZO-NR orientation misalignment from the c -axis. Remarkably, a monotonic increasing J c ( H ) with BZO 1D APCs concentration has been obtained in the BZO DD samples. Such a microstructure change is evidenced in the much smaller c-lattice parameter expansion of 0.103% in the DD samples as opposed to 0.511% in the SD counterparts and reduced c -axis alignment of the BZO 1D APCs as revealed in TEM. This yields a mixed 1D + 2D + 3D APC morphology and enhanced isotropic pinning with respect to the orientation of the H -field in the BZO DD samples.