The high-pressure synthesis of MgB2

The high-pressure synthesis is one of the most promising methods to produce MgB2 superconductive (SC) material. The available high-pressure apparatuses have working volume up to 100 cm3 which allows samples up to 60 mm in diameter to be manufactured. By a short-term (1h) high-pressure (2GPa) synthesis from Mg and B we have obtained samples 2.4-2.5 g/cm3 in density, 12.1-15.6 GPa in microhardness (under 4.96 N load), 170-200 kA/cm2 at 10 K and 58-62 kA/cm2 at 20 K in critical current density at a magnetic field of 1T. Samples demonstrated 8.5 T irreversible field at 10 K and 5.5 T at 20 K. The Ta positive influence on SC properties of MgB2 has been observed.