The high-pressure synthesis and superconductivity of MgB2 intermetallic compounds were studied. The compounds were obtained by high-pressure sintering of mixtures of Mg and B fine powders under 5.0GPa and at ~1000C for 0.5h. Magnetic measurements using a SQUID magnetometer revealed a sharp bulk superconducting transition above 39K. Four-probe direct-current resistivity measurements indicated a highly-conductive normal state and sharp superconducting transition. The results highlighted that high-pressure synthesis would be a promising way to promote studies of this kind of intermetallic superconductor.

High-Pressure Synthesis of MgB2 Superconductor with TC Above 39K. S.Li, J.Zhu, R.Yu, F.Li, Z.Liu, C.Jin: Chinese Physics, 2001, 10, 338-9