Enhanced performance of GdBCO bulk superconductors by doping a new kind of YGdBa₄CuNbO_y nanoparticles

In this work, a new kind of YGdBa4CuNbOy (YGdNb-11411) nano-particles was designed and sintered using a solid-state reaction method, whereas their impact on the performance of GdBCO bulks was investigated for the first time. From the acquired x-ray diffraction data and scanning electron microscopy imaging results, it was proved that the YGdNb-11411 particles were of excellent chemical stability and did not react with other phases during the crystal growth process. The YGdNb-11411 particles ranged from 80 to 130 nm and they were uniformly distributed in the well-textured GdBCO bulk superconductors. The maximum critical current density (J(c-max)) of the samples was enhanced from 3.48 x 10(4) A cm(-2) to 8.63 x 10(4) A cm(-2) (77 K) in the self-field as the doping amount increased from 0 wt% to 7 wt%. In addition, the GdBCO sample with YGdNb-11411 particles also showed an enhanced flux pinning force density and relatively high J(c) around the magnetic flux density range of 1 T-2 T (77 K). These results clearly indicated that the YGdNb-11411 particles could effectively enhance the properties of the GdBCO bulk superconductors.