Altınkök, AtılganYetiş, HakanOlutaş, MuratKılıç, KıvılcımKılıç, AtillaÇetin, Oktay2021-06-232021-06-2320061742-6588https://doi.org/10.1088/1742-6596/43/1/171https://hdl.handle.net/20.500.12491/59447th European Conference on Applied Superconductivity -- SEP 11-15, 2005 -- Vienna Univ Technol, Vienna, AUSTRIAWe have investigated the voltage response of superconducting polycrystalline bulk Y(1)Ba(2)Cu(3)O(7-x) (YBCO) material to a bidirectional square wave current with long periods and dc current by means of the evolution of the voltage-time (V-t) curves near the critical temperature. In a well-defined range of amplitudes and periods of driving current, and temperatures, it was observed that a non-linear response to bidirectional square wave current rides on a time independent background voltage value and manifests itself as regular sinusoidal-like voltage oscillations. It was found that the non-linear response disappears when the bidirectional current was switched to dc current. The spectral content of the voltage oscillations analyzed by the Fast Fourier Transform of the corresponding V-t curves revealed that the fundamental harmonics is comparable to the frequency of bidirectional square wave current. The coherent voltage oscillations were discussed mainly in terms of the dynamic competition between pinning and depinning together with the disorder in the coupling strength between the superconducting grains (i.e Josephson coupling effects). The density fluctuations and semi-elastic coupling of the flux lines with the pinning centers were also considered as possible physical mechanisms in the interpretation of the experimental results.eninfo:eu-repo/semantics/closedAccessCoherent VoltageSuperconductingPolycrystallineOscillationsConference Object10.1088/1742-6596/43/1/171436987012-s2.0-33746316750N/AWOS:000277479400171N/A