Dynamic of vortices in YBa 2 Cu 3 O 7–δ single crystal near the temperature of the vortex glass transition by the use of voltage noise measurements

Autor: A. Ramzi, S. Senoussi, A. Labrag, A. Taoufik, A. Abaragh, M. Bghour, A. Bouaaddi
Rok vydání: 2006
Předmět:
Zdroj: physica status solidi c. 3:3057-3060
ISSN: 1610-1642
1862-6351
DOI: 10.1002/pssc.200567029
Popis: We have studied the voltage noise Vn and the voltage noise spectral density SV of YBa2Cu3O7–δ superconductor in the regime of high magnetic field. Our studies were performed in a large range of temperature T (70 K-90 K) covering the vortex-glass - vortex-liquid transition which appears at Tg temperature. The sample is driving by a current I = 1 nA, under a different high magnetic fields H (2.4 T, and 5 T). The noise spectral density noted SV(f) exhibits a 1/fα. Approaching Tg the vortex glass transition, the voltage noise spectral density SV(T) is found to vanish critically according to the critical power law SV ∝ (T-Tg)x, with x = 1.64 ± 0.1 which represents the critical exponent. The behaviour exhibited by Sv(T) cannot be simply interpreted by thermal fluctuations as we conclude by comparing SV(T) with (dR/dT)2 curve. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE
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