Effect of Au nano-particles doping on polycrystalline YBCO high temperature superconductor

In this research, we prepared different Au nanoparticles (0.1-2 wt%) doped YBCO high temperature superconductor samples by sol-gel method. To characterize the samples, we used X-Ray diffraction (XRD) and scanning electron microscope (SEM) analysis. Results show the formation of orthorhombic phase of superconductivity for all prepared samples. We observed that by adding Au nanoparticles, the grains' size of the samples reduces from 76 nm to 47 nm as well. The critical current density (J(c)) and transition temperature (T-c) were determined using current versus voltage (I-V) and resistivity versus temperature (rho-T) measurements, respectively. We found that by increasing Au nanoparticles in the compound, in comparison to the pure YBCO sample, the transition temperature, pinning energy and critical current density will increase. Also, the highest J(c) is for 1 wt% Au doped YBCO compound that its critical current density is about 8 times more than the J(c) of pure one in 0.7 T magnetic field. (C) 2016 Elsevier B.V. All rights reserved.