Synthesis and characteristics of the ceramic superconductors in the Y1Ba2Cu3−xTixOy system

Bulk specimens of the ceramic superconducting material with the composition Y1Ba2Cu3−xTixOy are synthesized using the solid state reaction technique. The effect of titanium concentration on the normal and superconducting state properties of Y1Ba2Cu3−xTiyOy superconducting compound has been studied for 0 ⩽ x ⩽ 0.1. No increase in the offset transition temperature Tcf has been observed for small concentrations of titanium. Tcf falls rapidly with the increase in x. X-ray diffraction studies show that lattice constants are not much affected with the change in x and single-phase (Y1Ba2Cu3Oy) specimens are obtained only for x = 0.00 and 0.0462. All other specimens contain impurity phases, Y2BaCuO5 being the main impurity phase. The transition width is found to increase with the presence of impurity phases. All the specimens exhibit a metallic character in the normal state. The room temperature resistivity and Hall coefficient are found to increase with the increase with the increase in x. The oxygen content 7 − δ decreases slightly with the increase in x, with δ lying between 0.00 and 0.16. These studies are very useful in understanding the mechanism of superconductivity in high Tc ceramic materials.