Enhancement of Tc(0) by Substitution of Gallium in the Bismuth-Based High-Tc Superconducting Material

We report the enhancement of the zero resistivity T _c(0) by 5.5 K i.e. from 104 to 109.5 K by substitution of gallium 1.34% of copper in the bismuth 2223 compound. A series of Ga-containing compounds Bi₂Pb_0.4Sr₂Ca₂Cu_{3? x} Ga _x O _y ( x =0.00, 0.02, 0.04, 0.06, and 0.08) are synthesized by the solid-state reaction method. The samples are characterized by measurements of their dc electrical resistivity and ac magnetic susceptibility and by the powder X-ray diffraction analysis. It is noted that the high- T _c (2223) phase increases from 57.55% in an undoped sample to 92.99% in samples containing a low concentration of gallium i.e. x ≤0.04.