The effect of Sm2O3 doping on Bi1.6Pb0.4Sr2Ca2-xSmxCu3Oy superconductors

SUMMARY The Effects of S1112O3 Doping on BU.6Pbo.4Sr2Ca2-sSmsCu30y Superconductors In this study, Bii.6Pbo.4Sr2Ca2-xSmxCu30y samples were produced by solid state reaction method. The superconducting properties of the Bii.6Pbo.4Sr2Ca2-xSmxCu30y system have been investigated by x-ray diffraction (XRD), Diffrential Thermal Analysis (DTA),, thermal expansion coefficient, Vickers hardness (Hv), scanning electron microscope (SEM), optical microscope, electrical resistivity (p-T), ac Susceptibility and critical current density (Jc). X-ray diffraction (XRD) data showed that the volume fraction of the high-Tc (2223) phase decreased and the low-Tc (2212) phase increased as the amount of samarium content was increased from x=0.0 to 0.01. At higher amount of samarium (x=0.1 to 1.5) there only exists the low-Tc phase. The thermal expansion coefficient decreased with the increase of Sm content. From the measurement of the Vickers hardness, increasing the Content of samarium in samples from x=0.0 to x=1.5 showed increasing value of hardness. SEM micrographs showed that the porosity in samples increased and inhomogenity appears with incereasing Sm content. It was found that the critical transition temperature (T0) decreased with increasing the amount of Sn^Oa in BSCCO system. Critical current density measurements were performed in liquid nitrogen temperature. Current densities of the samples were decreased by increasing amount of Sm concentrations from x=0.0 to 0.1. The critical current densities of the samples with higher Sm concentrations from x=0.5 to 1.5 can not be measured. Because, it was estimated that temperatures of samples were lower than liquid nitrogen temperature (77K). Key Words: Superconductors, Doping Of Sm203, Thermal Expansion Coefficient, Vickers Hardness, Transition Temperature, Critical Current Densities. VI