Indexed on: 01 Jun '03Published on: 01 Jun '03Published in: Physics - Superconductivity
The MgB2 - based material high-pressure synthesized at 2 GPa and 800 C 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 (jc) higher than 100 kA/cm^2 at 33 K in 0 T field and at 20 K up to 3 T. At 20 K the critical current density higher than 10 kA/cm^2 was observed up to 5 T field. In the magnetic field up to 2 T high-pressure synthesized MgB2 (with 10 % of Ti) at 20 K behaves in the same manner as Nb3Sn at 4.2 K. In XRD patterns of magnesium diboride with the Ti added, we observed no evidence of titanium diboride or 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 irreversible field in the temperature range of 25-10 K contained some amount of pure Mg that was rather homogeneously dispersed in the material. The critical currents and irreversible fields of magnesium diboride synthesized at high pressure with Ti added are higher than those in the case where Ta has been added.