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 Tcon = 6K was obtained. The great influence of oxygen deficience on superconductivity is evident. Also, the incorporation of Pb adjusted the modulation pattern.