| Popis: |
The binary metallic magnesium diboride (MgB 2 ) is a promising superconductor with a remarkably high transition temperature of 39 K. The upper critical field H c2 ( T ) of MgB 2 is strongly influenced by the two-gap nature of the superconductivity in this material and can be enhanced by strong impurity scattering. This was particularly demonstrated for thin films. MgB 2 has a great potential for high current–high-field applications, because grain boundaries are no barriers for the current flow, but rather useful as pinning centers. Long MgB 2 wires produced by the low-cost powder-in-tube processing route are meanwhile commercially available. |
