Effects of columnar defects on the superconducting properties of Y1Ba2Cu3O7−δ: Limits to the irreversibility line

✍ Scribed by D.K. Christen; S. Zhu; C.E. Klabunde; H.R. Kerchner; J.R. Thompson; R. Feenstra; L. Civale; J.M. Phillips

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 161 KB
• Volume: 194-196
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)91412-5

✦ Synopsis

A series of YBa~Cu30 7 8(YBCO) epitaxial films and crystals were irradiated with energetic heavy ions (Sn 30+ or Ag29+ at energy 0.58 GeV) to produce columnar defects of highly disordered material.

The irreversibility lines, B*(T}, show enhancement due to the increased pinning. However, while B* does not exceed that observed in the highest-J c as-grown epitaxial thin films, the values approach the proposed vortex melting line determined by a number of experiments on nearly defect-free single crystals. These results are interpreted in terms of the predicted upper limit of pinning energies in anisotropic superconductors, and the thermally-induced decoupling of vortex segments.