Trapped field potential of commercial Y-Ba-Cu-O bulk superconductors designed for applications

Abstract

Bulk high-temperature superconductors (HTSs) that act as a trap field magnet establish a novel type of magnetic field source, which is significantly different from that of a permanent magnet or solenoid; therefore, they can be potentially used in magnetic-force-based applications. However, the primary issues related to the commercial use of the bulk HTS technology are established on the enhancement of trapped magnetic fields, as well as their reliability and reproducibility at temperatures achievable with off-the-shelf cryocoolers. This study presents experimental investigations on the strong trapped magnetic fields observed in commercial Y-Ba-Cu-O bulk HTSs produced as a double-sample stack, a cylindrical bulk, and a ring-shaped bulk. Consequently, a reliable and reproducible magnetic field of 9.5 T at 50 K was trapped in commercial Y-Ba-Cu-O assembled as a double-sample stack. In this case, shrink-fit encapsulation with either aluminum or stainless steel tube ensured equally effective reinforcement. Higher magnetization, although accompanied with partial flux jumps, yielded a trapped field of 16.85 T at 30 K, which is comparable to the reported record trapped fields. Finally, a maximum trapped field of 9.78 T -the strongest trapped field reported to date -was attained in the 6 mm hollow space of the ring-shaped bulk HTS.

Effect of thickness on magnetic properties of single domain GdBCO bulk superconductors

“…In Ref. [17], Vakaliuk et al mentioned that commercial YBCO assembled as a double-sample stack trapped a reliable and reproducible magnetic field of 9.5 T at 50 K and trapped field of 16.85 T at 30 K, which is comparable to the record reported. Durrell et al found that the highest trapped field currently peaks at 17.6 T (26 K) in a magnetizing field of 17.8 T, which is produced by Ag-doped GdBCO stacking samples.…”

Reliable 4.8 T trapped magnetic fields in Gd–Ba–Cu–O bulk superconductors using pulsed field magnetization

“…The peak trapped field, BT, surpasses comprehensively the field generated by conventional PMs, e.g. NdFeB, at temperatures below 70 K [4][5][6][7]. Large, single-grain GdBCO-Ag samples [8] and uranium-doped and irradiated YBCO samples have been shown to exhibit maximum trapped fields exceeding 2 T at liquid nitrogen temperature [9].…”

Direct fabrication of high-quality ring-shaped REBa2Cu3O y bulk magnets by the single-direction melt growth (SDMG) method

“…31,32) Based on our current understanding, the highest B T,max values at 77 K achieved inside a ring to date are 1.13 T for a single ring-bulk, and 2.59 T for an assembly of 10 stacked ring-bulks, respectively. 33,34) For all samples, #Dy1-#Dy3, we successfully grew crackfree ring-shaped REBCO bulks as shown in Fig. 1(b), which exhibited the glossy appearance characteristic of melt-textured bulks.…”

“…not-stacked, ring-bulks across all reported sizes. O. Vakaliuk et al reported a B T value of 1.13 T at 77 K inside a YBCO ring-bulk similar in size to the #Dy3, (28.1 mm OD , 6.0 mm ID , 17.3 mm t ), and this ring-bulk trapped up to 9.78 T when cooled to 25 K. 33) We anticipate that cooling our bulk to low temperatures will enable the realization of an internal magnetic field exceeding 10 T.…”