Weak Links and Phase Slip Centers in Superconducting MgB 2 Wires Academic Article uri icon


  • Abstract MgB 2 superconducting wires were produced by the Mg diffusion method. Scanning electron microscopy (SEM), optical microscopy, dispersive X-ray analysis (EDS), and XRD diffraction were used to study the physical structure and content of the wires. Magnetic properties (T cm, H c1, H c2, J c by the Bean model) were obtained with a SQUID magnetometer, and transport properties (T cr, H c2, resistivity and residual resistivity ratio) were measured using a standard four-lead configuration. The VI characteristics of the wires close to the critical temperature showed a staircase response, which was attributed to the presence of weak links, creating phase slip centers. The origin of those weak links is discussed in relation to their formation and structure.

publication date

  • January 1, 2004