Research Information System
APPLIED SUPERCONDUCTIVITY, vol.1, pp.559-566, 1993 (SCI-Expanded)
The sensitivities of the crystal structure and physical properties to the oxygen uptake have been studied for 110 K Pb doped Bi superconductor. The formal copper valency in the single superconducting phase samples increasing between 2.188 and 2.312 was determined by chemical technique. There are no lower T(c) phases and no line splitting in the x-ray diffraction pattern of the reannealed samples. However, two extra peaks were observed and these peaks become stronger with increasing oxygen content, the symmetry of the crystal structure stays unchanged. Furthermore, TGA experiments under different atmospheres have shown that the oxygen stoichiometry can be controlled in a reversible and systematic way by changing the oxygen partial pressure.