Batch-processing and bonding of melt-textured YBCO for motor applications

Growth-related profiles of remanent flux in bulk melt-textured YBaCuO crystal magnetized by pulsed fields

“…To avoid unwanted consequences that could be induced by cracks and other macroscopic imperfections, we have knowingly selected rather homogeneous YBa 2 Cu 3 O 7−δ (YBCO) sample (Figure 1). This was sinthesized from the mixture of commercially purchased powders (Solvay GmbH, Germany) with 1 wt.% CeO 2 by the melt-processing technique [12] and post-annealed in oxygen atmosphere. The bulk thus prepared was a cylinder with a diameter of 30 mm and a thickness of 18 mm.…”

Superconductor Permanent Magnets for Advanced Propulsion Applications

“…Textured grains can be as large as several centimeters in diameter, with a critical current density, J C , a few times 10 5 A/cm 2 (Fuchs et al, 1996;Chen et al, 1991;Salama and Lee, 1994;Lo and Salama, 2000;Lo et al, 2000a) at 77 K, and with applied magnetic fields up to 3 T (Muralidhar and Murakami, 1998;Litzkendorf et al, 1998). In addition, REBCO superconductors are very anisotropic, with supercurrents essentially confined to flow in copper-oxide planes.…”

YBa2Cu3O7‐δ superconductor bulks composited by Y2BaCuO5 nanoparticles derived from homogeneous nucleation catastrophe

“…With respect to the former, Zhou et al used Y 2 BaCuO 5 powders smaller than 500 nm by ball milling . Li et al adopted microemulsion method to produce Y211 powders with a size distribution between 30 and 100 nm, and Shi et al produced nanosized Y211 (~12 nm) and Y123 (~30 nm) powders by using carbon nanotube templates . Evidently, those methods are effective to reduce the size of Y211.…”

“…High-temperature superconductor (HTS) bulks of REBa 2-Cu 3 O 7-d (RE=Nd, Sm, Y) materials, possessing high critical current density (J c ) and high trapped magnetic field, have attracted a significant amount of attention, owing to their potentials for device applications, [1][2][3][4][5] such as hysteresis motors and magnetic bearings. [6][7][8] Among them, the Y123 bulk has become preferentially applicable superconductor bulks for industrial production because of its mature processing technique, top-seeded melt growth (TSMG). In that process, the precursor powder of YBa 2 Cu 3 O 7-d (Y123) plus Y 2 BaCuO 5 (Y211) is commonly employed.…”

“…10 Li et al adopted microemulsion method to produce Y211 powders with a size distribution between 30 and 100 nm, 11 and Shi et al produced nanosized Y211 (~12 nm) and Y123 (~30 nm) powders by using carbon nanotube templates. 8 Evidently, those methods are effective to reduce the size of Y211. However, note that the Y211 phase as a precursor material in the prior art techniques commonly result in its size enlargement caused by two physical phenomena, coarsening and epitaxial growth.…”