Current-induced voltage oscillations in superconducting Y1Ba2Cu3O7-δ
Abant Izzet Baysal University, Department of Physics, Turgut Gulez Research Laboratory, 14280 Bolu, Turkey
Corresponding author: a email@example.com
Revised: 5 October 2005
Published online: 16 December 2005
We investigated influence of bidirectional square wave current with long periods and dc current on the evolution of the voltage-time () curves in superconducting polycrystalline bulk Y1Ba2Cu3O7-δ (YBCO) material at the temperatures near the critical temperature. In a well-defined range of amplitudes and periods of driving current, and temperatures, novel type of non-linear dynamic responses was observed by means of the curves. It was seen that such a non-linear response to bidirectional square wave current sometimes reflects itself as regular sinusoidal-like voltage oscillations. The sinusoidal-like and non-sinusoidal oscillations were discussed mainly in terms of the dynamic competition between pinning and depinning and significant relaxation effects which appear in this competing process. The density fluctuations associated with the current induced self-magnetic flux (SMF) lines and semi-elastic coupling of SMF lines with the pinning centers were also considered as possible physical mechanisms in the interpretation of the experimental results.
PACS: 74.72.Bk – Y-based cuprates / 74.25.Qt – Vortex lattices, flux pinning, flux creep
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005