Anisotrophic currents and flux jumps in high-Tc superconducting films with self-organized arrays of planar defects

Authors

V Yurchenko, University of Oslo
A.J Qviller, University of Oslo
P.B Mozhaeva, Dept Physics Technical University of Denmark
J.E Mozhaeva, Dept of Physics Technical University of Denmark
J.B Hansen, Dept of Physics Technical University of Denmark
C Jacobsen, University of Denmark,
I.M Kotelyanskii, Institute Radio Engineering Electronics Russia
Alexey V. Pan, University of WollongongFollow
T H. Johansen, University of OsloFollow

RIS ID

33775

Publication Details

Mozhaeva, P. B.., Mozhaeva, J. E.., Qviller, A. J.., Hansen, J. B.., Johansen, T., Kotelyanskii, I., Yurchenko, V. V.., Pan, A. V. Jacobsen, C. S.. (2010). Anisotrophic currents and flux jumps in high-T_c superconducting films with self-organized arrays of planar defects. Physica C: Superconductivity and its Applications, 470 (19), 799-802.

Abstract

Regular arrays of planar defects with a period of a few nanometers can be introduced in superconducting YBa₂Cu₃O_7-δ (YBCO) thin films by depositing them on vicinal (also called miscut or tilted) substrates. This results in the anisotropy of critical currents flowing in the plane of the film. We present results of real-time magneto-optical imaging (MOI) of magnetic flux distribution and dynamics in a series of YBCO thin films deposited on NdGaO₃ substrates with different miscut angles θ. MOI allows reconstructing the current flow profiles. From the angle formed between domains with different directions of the current flow we determine the anisotropy parameter of the in-plane current, as well as its field and temperature dependences. The artificially introduced defects also have a dramatic effect on the dynamics of the flux propagation: for 10°<θ<14° the magnetic flux propagates along the easy channels intermittently, i.e. in a form of flux jumps. This behavior is indicative of thermo-magnetic instability in superconductors, but we argue that this effect can be of a different nature.