Phase formation, activation energy and superconductivity of MgO nanoparticles added (Cu0.5Tl0.5)Ba2Ca2Cu3O10-δ phase

A well-established solid-state reaction route was adopted for the synthesis of (Cu0.5Tl0.5)Ba2Ca2Cu3O10-δ {(CuTl)-1223} superconducting phase and a well-known sol-gel method was used to prepare the magnetism oxide (MgO) nanoparticles. The different weight percentages of these MgO nanoparticles were mixed with (CuTl)-1223 superconductor to obtain (MgO)x/(CuTl)-1223; x = 0 ∼ 5.0 wt.% nanoparticles-superconductor composites. The phase formation, crystal structure, phase purity and morphology of MgO nanoparticles and (MgO)x/(CuTl)-1223 composites were investigated by X-rays diffraction and scanning electron microscopy, respectively. Superconducting properties of (MgO)x/(CuTl)-1223 composites were explored by resistivity versus temperature measurements. The holes' concentration, activation energy and zero resistivity critical temperature were suppressed while transition width was broadened, which can be attributed to the reduced superconducting volume fraction and enhanced number of scattering centers with increasing contents of insulating MgO nanoparticles in the host (CuTl)-1223 superconducting phase.