Abstract
Superconducting samples of type Bi1.8Pb0.4Sr2Ca2.1Cu3-x Ru (x) O10+delta , (Bi, Pb)-2223, with 0.0 <= x <= 0.4 and type Tl0.5Pb0.5Sr1.6Ba0.4CaCu2-x Ru (x) O7-delta , (Tl, Pb)/Sr-1212, with 0.0 <= x <= 0.525 were synthesized using the standard solid-state reaction technique. The lattice parameters and the surface morphology for these samples were determined using X-ray powder diffraction (XRD) and scanning electron microscope (SEM) measurements, respectively. All element-contents of the samples prepared were estimated from the electron dispersive X-ray (EDX) technique, and their results were compared with those obtained from particle-induced X-ray emission (PIXE). In addition, the oxygen-content was determined using elastic Rutherford backscattering spectroscopy (RBS) technique at 3 MeV proton beam. The superconducting transition temperature T (c) and the hole carrier concentration P were determined from the electrical resistivity measurement. The data of both T (c) and P for Bi1.8Pb0.4Sr2Ca2.1Cu3-x Ru (x) O10+delta and Tl0.5Pb0.5Sr1.6Ba0.4CaCu2-x Ru (x) O7-delta phases increased up to x=0.05 and 0.075, respectively and then they decreased as x increased. The superconductivity was completely destroyed around x=0.4 and 0.525 for (Bi, Pb)-2223 and (Tl, Pb)/Sr-1212 phases, respectively. The normal-state electrical resistivity data were analyzed using the two and three dimensional variable range hopping (2D-VRH and 3D-VRH) and the Coulomb gab (CG).