No abstract

The effects of nano-sized PbO (10-30 nm) addition on the critical temperature, transport critical current density (Jc) and flux activation energy of YBa2Cu3O7-δ (PbO)x (x = 0.00-0.45 wt.%), prepared by the standard solid-state reaction method were studied. Powder X-ray diffraction method, electrical resistance measurements and scanning electron microscopy have been used to study the samples. The transport critical current density, Jc was measured using the four-point probe method. The flux activation energy, U was calculated from the resistivity versus temperature measurements using the Arrhenius-type equation. The highest superconducting onset temperature Tc onset was observed in the sample with x = 0.35 wt. % (94 K). The x = 0.25 wt. % sample showed the highest Jc. The activation energy (U = 0.90 eV) in zero fields showed a maximal plateau between x = 0.20 and 0.35 wt. %. Enhancement of Jc was explained as the increase in the activation energy as a result of nano-sized PbO addition.