INSULATOR TO SUPERCONDUCTOR TRANSITION OF Pb DOPED 2201 SINGLE CRYSTAL IN Bi-SYSTEM BY OXYGEN DEFICIENCY

Flux method was used to grow large 2201 single crystal in Bi-Sr-Cu oxide. The as-grown crystal was nonsuperconductor and showed semiconductivity in resistivity curve. After it was reduced in flowing N₂ at 570°C and appropriate oxygen vacancies were induced, superconductivity with T^on_c=6K was obtained. The great influence of oxygen deficience on superconductivity is evident. Also, the incorporation of Pb adjusted the modulation pattern.