Cobalt substitution effects on critical current, inter-grain full penetration field, and critical temperature study for Tl2Ba2Ca2Cu3-xCoxOy bulk superconductor, where x is from 0.005 to 0.050

Abstract

Thallium-based cuprates are known to exhibit high critical temperatures and currents. Usually, partial substitution of copper by transition elements leads to the suppression of superconducting properties. This contribution reports on the studies of Tl2Ba2Ca2Cu3-xCoxOy. All specimens were found to be superconductors with critical temperatures of 102.4 K, 112.9 K, 112.2 K, 113.5 K, 112.8 K, and 94.8 K for x = 0.005, 0.010, 0.020, 0.030, 0.040, and 0.050, respectively. The samples were characterised by scanning electron microscopy, X-ray diffraction, AC susceptibility, resistance, and vibrating sample magnetometry.