Structural and transport properties of Bi2Sr2-xMxCuO6±δ (M=Bi and Pb)

Article abstract of DOI:10.1016/0921-4534(91)90699-Y

Solid solutions of Bi₂Sr_2-xM_xCuO_6±δ (M=Bi or Pb) were prepared with 0.1 ≤x≤0.5 for M=Pb and 0.2≤x0.5 for M=Bi. Both Pb and Bi are effective in stabilizing the 2201 phase, when substituted for Sr. However, the Pb substitution induces a pseudotetragonal to orthorhombic phase transition. Variation of the unit cell parameters and δ with x in Bi₂Sr_2-xPb_xCuO_6±δ, suggest that Pb is in the Pb^IV formal oxidation state and appears to substitute at least partially for the Bi site. No evidence for superconductivity was observed for either substitutions in the 'as prepared' samples, regardless of the value of x. However, annealing a sample of Bi₂Sr_1.9Pb_0.1CuO_6±δ in inert atmosphere showed the onset of superconductivity at approximately 8 K.