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[Formula: see text]011 TSIG process with a new solid phase of [(100-[Formula: see text])(Y2O[Formula: see text]BaCuO2)+[Formula: see text]ZnO] and a new liquid phase of (Y2O3+6CuO+10BaCuO2). The effects of ZnO additions on the growth morphology, microstructure, critical temperature ([Formula: see text]), the levitation force and trapped field of the YBCO bulks have been investigated. It is found that within the range of ZnO additions [Formula: see text]=0–1.0 wt.%, all the samples are of the typical characteristic of single-domain YBCO bulk; the [Formula: see text] of the samples decreases from 92 K to 80 K when the ZnO addition [Formula: see text] increases from [Formula: see text]=0 wt.% to [Formula: see text]=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[Formula: see text] for Cu[Formula: see text] 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 [Formula: see text]=0.1 wt.%, respectively. This result is significantly important and helpful for us to improve the properties of YBCO bulk superconductors.