Magnetic flux channelling in YBa2Cu3O7-δ films grown by a chemical solution deposition technique on vicinal and non-vicinal substrates

¹Department of Physics, University of Oslo, PO Box 1048 Blindern, 0316 Oslo, Norway.

²Department of Energy Conversion and Storage, Technical University of Denmark, Roskilde 4000, Denmark.

³Department of Electrical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Minhang, Shanghai, China, 200240

⁴The Key Laboratory of Advanced Functional Materials, Ministry of Education, Beijing University of Technology, Beijing 100022, China

⁵Norwegian Defence Research Establishment (FFI), Kjeller, Norway

⁶Institute for Superconducting and Electronic Materials, University of Wollongong, Northfields Avenue, Wollongong,NSW 2522, Australia

Adv. Mater. Lett., 2017, 8 (12), pp 1204-1210

DOI: 10.5185/amlett.2017.1474

Publication Date (Web): Sep 08, 2017

Copyright © IAAM-VBRI Press

E-mail: pavlo.mikheenko@fys.uio.no

Abstract

Magneto-optical imaging of YBa₂Cu₃O_7-δ films with high critical current density, synthesized by a cost-effective metal organic decomposition technique reveals inhomogeneous flux penetration in the specimens in the form of thin parallel lines. The origin of such a stripy pattern and its dependence on the sample preparation conditions and state of substrate is discussed. The stripes reflect accumulation of planar defects forming parallel lines of reduced in-plane critical current density, j_c, perpendicular to planar defects and enhanced j_c parallel to them. Such channel-like reduction and corresponding enhancement of j_c is especially expressed in a sample deposited on vicinal substrate, which, as a consequence, demonstrates global temperature-dependent in-plane anisotropy with an anisotropy ratio up to 2.4. The directional enhancement of critical current density due to planar defects could be beneficial for practical use of superconducting films. 

Keywords

Magneto-optical imaging, superconducting films, YBCO, metal-organic deposition.