Fabrication of high levitation force and trapped field single-domain GdBCO/CeO 2 bulk by doping Gd 2− r Y r -411 nano-particles using the Gd + 011 TSIG method

Abstract In this work, the effect of Y content on Gd 2− r Y r Ba 4 CuNbO y ( r = 0, 0.6, 1, 1.4, 2, Gd 2− r Y r -411) nano-powders was thoroughly explored for the first time. The results demonstrate that Y doping can effectively modulate the particle size of Gd 2− r Y r -411 nano-particles. The GdBCO bulks with solid phase compositions of [92 wt% (Gd 2 O 3 + 1.2BaCuO 2 ) + 7 wt% Gd 2− r Y r -411 + 1 wt% CeO 2 ] were prepared using the Gd + 011 top-seeded infiltration and growth method. The results indicated that both the levitation force ( F L ) and the trapped field ( B tr ) of the sample initially increased and then decreased with the Y content in the doped Gd 2− r Y r -411 nano-powders increased. The optimal values of F L (159 N at 77 K, 0.5 T) and B tr (0.92 T at 77 K, 1 T) of the sample were achieved by doping 7 wt% GdY-411 nano-powder, which were enhanced by 48 N and 0.22 T over the undoped sample. The calculated maximum levitation force density of the sample reached up to 19.8 N cm −2 . A B tr of 1.23 T has been recorded finally at 77 K for the GdBCO/CeO 2 contained GdY-411 with 32 mm diameter. The above results demonstrate that the interface defects generated by Gd 2− r Y r -411 nano-particles can serve as effective magnetic flux pinning centers, which enhances the performance of the samples. In addition, compared with the doping of the traditional RE2411, the F L and B tr increased by over 35% and 21%, respectively. Our work provides systematic reference for studying the influence of mixed rare earth type nano-powders on the performance of REBCO bulk superconductor.