Abstract
The solid-state reaction was used to prepare three different high-temperature superconductors, namely Tl0.85Cd0.15Sr2CuO5−δ, Tl0.85Cd0.15Sr2Ca2Cu2O7−δ and Tl0.85Cd0.15Sr2Ca2Cu3O9−δ. The optimum calcinations were performed at 800∘C, and the sintering was performed within 855–860∘C. The samples were tested before and after oxygen treatment. It has been found that the oxygen flow on samples during preparation produces high-phase superconductors as compared with the samples prepared without oxygen flow. The four-probe techniques were used to measure the electrical resistivity to know the transition temperature (Tc). It was found that the samples which were prepared with oxygen flow have the highest zero-transition temperatures (Tc(offset)) of 85, 106 and 121 K for the samples Tl0.85Cd0.15Sr2CuO5−δ, Tl0.85Cd0.15Sr2Ca2Cu2O7−δ and Tl0.85Cd0.15Sr2Ca2Cu3O9−δ, respectively. X-ray diffraction spectrum showed all samples are polycrystalline with a tetragonal structure and also showed an increase of the c-axis and lattice constant with the increase of CuO layers and oxygen content. It was noticed that the change of CuO layers of all samples produced a modification in the transition temperature, mass density (ρm) and c/a parameter.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
