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

Abstract

Single domain YBCO bulk superconductors with different additions of ZnO have been successfully fabricated by RE+011 TSIG process with a new solid phase of [(100 − x)(Y 2 O 3 +1.2BaCuO 2 )+xZnO] and a new liquid phase of (Y 2 O 3 +6CuO+10BaCuO 2 ). The effects of ZnO additions on the growth morphology, microstructure, critical temperature (Tc), the levitation force and trapped field of the YBCO bulks have been investigated. It is found that within the range of ZnO additions x = 0-1.0 wt.%, all the samples are of the typical characteristic of single-domain YBCO bulk; the Tc of the samples decreases from 92 K to 80 K when the ZnO addition x increases from x = 0 wt.% to x = 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 2+ for Cu 2+ 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 x = 0.1 wt.%, respectively. This result is significantly important and helpful for us to improve the properties of YBCO bulk superconductors.

Variation of Pinning Force Density Throughout the TSMG Y123 Superconductor with Location

“…It is possible to produce large single-grained samples aligned in the c-axis direction with the melting methods and especially top seed melt growth (TSMG) and infiltration growth (IG) methods are promising. Generally, seeds having a higher melting temperature and a similar crystal structure to the main sample are used in these methods [7][8][9][10][11][12].…”

Effects of Zn doping on superconducting properties of melt textured Y–Ba–Cu–O bulk superconductors

“…González et al also presented the enhancement of J c by ZnO doping, and found that ZnO doping with the amount up to 0.6% will not significantly affect the size and distribution of Y211 particles [33]. Yang et al fabricated bulks by RE + 011 TSIG process and obtained increment of 21.1% and 30.4% in levitation force and trapped field respectively when 0.1 wt% ZnO was added to YBCO at 77 K [34].…”