  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.
