Abstract

The temperature dependence of the DC resistivity and AC magnetic susceptibility was investigated in bulk ceramics of the BiPbSrCaCuO system with 2212-free (2223) phase. The temperature domain needed to synthesize this phase was small and, according to the actual temperature used, the superconducting properties of the samples were strongly modified. The corresponding X-ray diffraction lines of the 110 K phase can be indexed in the pseudo-orthorhombic unit cell with parameters 5.40×5.41×37 Å3. SEM microprobe study revealed the presence of several non-superconducting phases and a composition 2.1:0.1:2:2:3 for the cation ratio Bi:Pb:Sr:Ca:Cu of the 110 K phase. Electrical measurements (DC resistivity and AC susceptibility) confirmed the existence of a 2212-free (2223) phase. A low temperature `tail' in the DC electrical resistivity marks the low value of critical current in the samples

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