Vortex-system ordering during magnetisation measurements in YBa2Cu3O7−δ films at low temperatures

✍ Scribed by L. Miu; Dana Miu; G. Jakob; H. Adrian

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 107 KB
• Volume: 460-462
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.04.050

✦ Synopsis

Zero-field-cooling dc magnetisation relaxation measurements performed on optimally doped epitaxial YBa 2 Cu 3 O 7Àd films with the external magnetic field H oriented parallel to the c-axis reveal the ordering of the creeping vortex-system in the low temperature T domain, due to the macroscopic currents induced in the sample. This dynamic ordering manifests itself through the appearance of a maximum in the T variation of the normalised vortex-creep activation energy. The location of this maximum in the H-T plane describes a well-defined current induced order-disorder line. Our results suggest the absence of a static elastic vortex glass in disordered high-temperature superconductors at high H, and the current induced ordering of the vortex-system as a possible origin for the current-voltage characteristic scaling in terms of an elastic vortex glass-vortex liquid transition.