Measurements and analysis of the noise spectral density of YBCO films

✍ Scribed by Taoufik, A. ;Bghour, M. ;Labrag, A. ;Bouaaddi, A. ;Abaragh, A. ;Ramzi, A. ;Senoussi, S. ;Tirbiyine, A.

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 973 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200567032

✦ Synopsis

Abstract

We studied the voltage noise spectral density S ~V~(f, T, H ) dependence on frequency f, temperature T and applied magnetic field H in YBa~2~Cu~3~O~7–δ~ films. The voltage noise spectral density S ~V~(f ) as a function of frequency exhibits 1/f behavior according to a Lorentzian shape A [(1 + π__f__ /f ~0~)^B^ ]^C^, where A, f ~0~, B, C constants which are determined and compared for many values of H . The influence of temperature and magnetic field is clearly observed as a function of temperature, S ~V~(T ) is found to vanish at T ~g~, the temperature of vortex glass transition, according to a (T – T ~g~)^x^ law. We interpreted those results by the formation of a large distribution of glass vortex domains. Approaching T ~g~, these domains grow in size and lifetime, while at T ~g~ those parameters diverge. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)