Sherif G Elsharkawy
Superconducting Properties of (Tl1.6Pb0.4)-2223 Substituted by Praseodymium
The lattice parameters, electrical resistivity, ac magnetic susceptibility, magnetoresistance and Hall effect have been measured for a newly developed compound obtained through partial substitution of Ca2+ ions by Pr3+ ones in (Tl1.6Pb0.4) Ba2Ca2Cu3O10-δ. For such compound, the prepared samples are almost single phase of (Tl, Pb)-2223 tetragonal unit cell with a space group 14/mmm. An opposite behavior for both lattice parameters a and c was observed as the concentration of Pr-content was increased. Also, metallic tendency was observed from electrical resistivity measurements in the range of 0≤x≤0.15 for temperature values above the superconducting transition temperature Tc. On the other hand, a semiconductor-like behavior was noticed for values x>0.15. Suppression in the superconducting transition temperature was found as the Pr-content was increased. This suppression in superconductivity for the system evolved was discussed according to two models point of views; the Cooper-pair breaking and hole-filling models. The transverse magnetoresistance, below the superconducting transition temperature, was measured in a weak magnetic field up to 4.8 kg. Finally, the Hall voltage was measured at different temperature values above that of superconducting transition using five-probe technique. The Hall coefficient, Hall mobility and Hall angle were expressed as functions of both temperature and Pr-content.