| 摘要 |
PROBLEM TO BE SOLVED: To provide a superconducting element containing magnesium diboride (=MgB<SB>2</SB>). SOLUTION: The superconducting element comprising at least one superconductive filament (1) of a size between 5 and 500 microns, which is enclosed in a metal matrix (2) and is also equipped with at least one high-conductivity ohmic element (4), the superconducting filaments that is separated from the matrix (2) and from the conductive ohmic element (4) by a protective metal layer (3) and formed by reaction between boron (B), as well as, magnesium (Mg) powder and boron carbide (=B<SB>4</SB>C) powder as a first additive, with one or a plurality of carbon-containing powder additives added, existing in the reaction of the powder mixtures containing Mg, B and B<SB>4</SB>C. Reaction of the powder mixtures to MgB<SB>2</SB>is carried out at a temperature range of 500 and 760°C, becoming a maximum of the critical current density, J<SB>c</SB>, at a temperature of 760°C or lower. COPYRIGHT: (C)2008,JPO&INPIT |
