High-pressure synthesis of MgB2 with addition of Ti

Magnesium diboride-based material high-pressure synthesized at 2 GPa and 800 degreesC for 1 h from Mg and B (taken in the stoichiometry ratio of MgB2) with addition of 2-10 wt.% of Ti demonstrated the critical current density (j(c)) higher than 100 kA/cm(2) at 20 K up to 3 T and at 33 K in 0 T field. At 20 K the critical current density higher than 10 kA/cm(2) was observed up to 5 T field. In the magnetic fields up to 2 T high-pressure synthesized MgB2 (with 10% of Ti) at 20 K has a critical current density comparable to that of Nb3Sn at 4.2 K. XRD patterns of magnesium diboride with Ti addition exhibited no evidence of unreacted titanium and only one compound with titanium was identified, namely, titanium dihydride TiH2 (or more strictly TiH1.924). The sample with the highest critical current density and the irreversibility field in the temperature range of 25-10 K contained some amount of rather homogeneously dispersed pure Mg and high amount of Mg-B inclusions. (C) 2003 Elsevier B.V. All rights reserved.