Influence of ZnO doping on the properties of single domain YBCO bulks fabricated by RE+011 TSIG process.

Single domain YBCO bulk superconductors with different additions of ZnO have been successfully fabricated by RE011 TSIG process with a new solid phase of [(100-)(Y₂OBaCuO₂)+ZnO] and a new liquid phase of (Y₂O₃+6CuO+10BaCuO₂). The effects of ZnO additions on the growth morphology, microstructure, critical temperature (), the levitation force and trapped field of the YBCO bulks have been investigated. It is found that within the range of ZnO additions =0-1.0 wt.%, all the samples are of the typical characteristic of single-domain YBCO bulk; the of the samples decreases from 92 K to 80 K when the ZnO addition increases from =0 wt.% to =1.0 wt.%; the levitation force and trapped field of the samples firstly increase and then decrease with increase of ZnO additions after going through a maximum, which is closely related with the ZnO addition and the resulting flux pinning force caused by lattice distortion due to the substitution of Zn for Cu site in the YBCO crystal; the largest levitation force 36.8 N (77 K, 0.5 T) and trapped field 0.416 T (77 K, 0.5 T) of the samples are obtained when =0.1 wt.%, respectively. This result is significantly important and helpful for us to improve the properties of YBCO bulk superconductors. [ABSTRACT FROM AUTHOR]