Ion Beam Analysis and Normal-State Conduction Mechanisms for (Bi, Pb)-2223 and (Tl, Pb)/Sr-1212 Superconducting Phases Substituted by Ruthenium

• Published in: Journal of superconductivity and novel magnetism 2012-02, Vol.25 (2), p.273-291
• Main Authors: Awad, R., Roumié, M., Abou-Aly, A. I., Mahmoud, S. A., Barakat, M. M.
• Format: Article
• Language: English
• Subjects: Carrier density; Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effects of material synthesis, crystal structure, and chemical composition; Electrical resistivity; Exact sciences and technology; Lead (metal); Magnetic Materials; Magnetism; Original Paper; Phases; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Scanning electron microscopy; Strongly Correlated Systems; Strontium; Superconductivity; Transition temperature variations; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); X-rays
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-011-1296-0

Superconducting samples of type Bi 1.8 Pb 0.4 Sr 2 Ca 2.1 Cu 3− x Ru x O 10+ δ , (Bi, Pb)-2223, with 0.0≤ x ≤0.4 and type Tl 0.5 Pb 0.5 Sr 1.6 Ba 0.4 CaCu 2− x Ru x O 7− δ , (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 Bi 1.8 Pb 0.4 Sr 2 Ca 2.1 Cu 3− x Ru x O 10+ δ and Tl 0.5 Pb 0.5 Sr 1.6 Ba 0.4 CaCu 2− x Ru x O 7− δ 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).