The ability of large-grain (RE)Ba2Cu3O7−δ ((RE)BCO; RE = rare earth) bulk superconductors to trap magnetic fields is determined by their critical current. With high trapped fields, however, samples are subject a relatively large Lorentz force, and performance limited primarily tensile strength. Consequently, sample reinforcement the key improvement in these technologically important materials. In this work, we report field 17.6 T, largest reported date, stack two silver-doped GdBCO...

Progress in superconducting bulk materials has been somewhat overshadowed by the considerable effort required to produce practical long-length conductors. There has, however, steady progress both science of and technologies use them effectively engineering applications. In particular, magnetised superconductors are capable acting as quasi-permanent magnets with potential providing magnetic fields several tesla or greater from a small volume material, they can act shields provide...

Strong evidence for high intergranular critical current densities and large bulk magnetic flux pinning in superconducting polycrystalline MgB2 has been observed. The presence of strongly-coupled grain boundaries this material confirmed by a dramatic collapse the hysteresis loop when specimen is ground into fine powder re-measured under similar conditions. Further strong intergrain links provided continuous variation remanent moment up to full penetration field sample. absence weak-link...

The ability to generate a permanent, stable magnetic field unsupported by an electromotive force is fundamental variety of engineering applications. Bulk high temperature superconducting (HTS) materials can trap fields magnitude over ten times higher than the maximum produced conventional magnets, which limited practically rather less 2 T. In this paper, two large c-axis oriented, single-grain YBCO and GdBCO bulk superconductors are magnetized pulsed magnetization (PFM) technique at...

Bulk (RE)-Ba-Cu-O [(RE)BCO] cuprate HTS have been developed steadily towards a wide range of sustainable engineering and technological applications since their discovery in 1986 based primarily on unique potential to trap very large magnetic fields (>5 T) at temperatures that are accessible potentially by thermo-electric cooling techniques. Trapped ∼10 T the surface individual (RE)BCO bulk single grains excess 17 reinforced two-sample stack now being achieved reliably. This paper reviews...

Abstract Recent findings using volumetric MRI techniques have revealed that patients with combat‐related and noncombat‐re‐lated posttraumatic stress disorder (PTSD) reductions in right hippocampal volume. Twenty‐one veterans PTSD eight age‐matched control were studied proton magnetic resonance spectroscopy to test the hypothesis N‐acetyl‐L‐aspartic acidkreatine (NAAICr) ratio would be decreased medial temporal lobe structures of compared controls. Patients displayed significantly lower...

A trapped field of over 3 T has been measured at 17.5 K in a magnetized stack two disc-shaped bulk MgB2 superconductors diameter 25 mm and thickness 5.4 mm. The samples were fabricated by uniaxial hot pressing, which is readily scalable, industrial technique, to 91% their maximum theoretical density. macroscopic critical current density derived from the data using Biot–Savart law consistent with local From this we conclude that density, therefore performance, limited flux pinning available...

Investigating and predicting the magnetization of bulk superconducting materials developing practical magnetizing techniques is crucial to using them as trapped field magnets in engineering applications. The pulsed (PFM) technique considered be a compact, mobile relative inexpensive way magnetize samples, requiring shorter times (on order milliseconds) smaller less complicated fixture; however, produced by PFM generally much than that slower zero cooling or techniques, particularly at lower...

Sintered samples of MgB2 were irradiated in a fission reactor. Defects the bulk microstructure are produced during this process mainly by 10B(n,α)7Li reaction while collisions fast neutrons with lattice atoms induce much less damage. Self-shielding effects turn out to be very important and lead highly inhomogeneous defect distribution samples. The resulting disorder enhances normal state resistivity upper critical field. irreversibility line shifts higher fields at low temperatures measured...

Single domain Y–Ba–Cu–O (YBCO) composed of a YBa2Cu3Oy (Y-123) superconducting bulk matrix with discrete, non-superconducting Y2BaCuO5 (Y-211) phase inclusions has been fabricated by seeded infiltration and growth (IG) technique in the form cylindrical pellets up to 32 mm diameter. Sample shrinkage radial direction for single domains prepared this is relatively low at 5% independent sample size, contrast observed samples grown conventional melt processing, which increases significantly...

Second-phase, nanoscale inclusions of composition Y2Ba4CuMOy (M=U, Nb, Ta, W, Mo, and Re), which form artificial pinning centers, have been introduced into large, single-grain [rare-earth (RE)]-Ba-Cu-O superconductors. A significant improvement in critical current density is observed these samples, due presumably to various combinations normal conducting, paramagnetic, geometrical properties the particles superconducting (RE)Ba2Cu3O7−δ (RE-123) phase matrix. These are chemically stable...

The critical current density, Jc, irreversibility field, Birr, and magnetic field trapping ability of (LRE)–Ba–Cu–O bulk superconductors, where LRE is a light rare earth element such as Nd, Sm, Eu Gd, are generally superior to those the more common melt-processed Y–Ba–Cu–O (YBCO). lack availability suitable seed crystal grow large, single grain superconductors with controlled orientation, however, has hindered severely development these materials for engineering applications over past ten...

Crossed-magnetic-field effects on bulk high-temperature superconductors have been studied both experimentally and numerically. The sample geometry investigated involves finite-size along (crossed-)magnetic-field directions. experiments were carried out melt-processed Y-Ba-Cu-O single domains that had premagnetized with the applied field parallel to their shortest direction (i.e., $c$ axis) then subjected several cycles of application a transverse magnetic $ab$ plane. properties measured...

The spin-dependent Compton profile of ferromagnetic iron has been measured with circularly polarized synchrotron radiation extracted at 46 and 62 keV from the Daresbury storage ring by viewing 5-T magnet 0.24 mrad above below electron orbital plane. For first time (to our knowledge) in a photon scattering experiment line shape is well established. negative magnetization resulting $s\ensuremath{-}p$ polarization evident here as 25% dip around zero momentum, which greater than that predicted...

Single-grain, (RE)–Ba–Cu–O [(RE)BCO)] bulk high-temperature superconductors have significant potential for application as trapped field magnets in a range of engineering devices. However, it is not trivial to fabricate single grains (RE)BCO due the complexity growth process, especially when sample diameter exceeds 25 mm. In particular, difficulties associated with seed crystal can lead poor grain or complete failure. We employed an optimized buffer technique, which was determined by...

Buffer-aided top seeded infiltration and growth (TSIG) with a suitable liquid phase reservoir has been compared the melt (TSMG) process applied successfully to fabricate single grain YBa2Cu3O7-δ​(YBCO) bulk superconductors. A Yb-based observed yield homogeneous, high density YBCO grains by TSIG technique. Sintering Y2BaCuO5(Y-211) preform prior found be critical in retaining shape of sample during process. number advantages have demonstrated, including dramatic reduction shrinkage general...

In this paper, the authors investigate numerically in-field behavior of high-temperature superconducting (HTS) coils and a method to potentially improve their performance using ferromagnetic material as flux diverter. The ability accurately predict electromagnetic superconductors in complex geometries environments is crucial design commercially viable superconductor-based electrical devices, such power transmission cables, fault current limiters, transformers, motors generators. analysis...

The melt processing of Y–Ba–Cu−O (YBCO) single grains has been investigated using different isothermal temperature profiles for precursor powders containing varying amounts Y-211. crystal morphology the as-grown YBCO and growth rate, which is influenced critically by initial Y-211 content under-cooling temperature, have analyzed. A simple method to determine an optimum profile bulk proposed based on results this investigation. influence macrosegregation inclusions crystallographic...

A trapped magnetic field of greater than 3 T has been achieved in a single grain GdBa2Cu3O7-δ (GdBaCuO) bulk superconductor diameter 30 mm by employing pulsed magnetization. The magnet system is portable and operates at temperatures between 50 K 60 K. Flux jump behaviour was observed consistently during magnetization when the applied field, Ba, exceeded critical value (e.g., 3.78 K). sharp dBa/dt essential to this phenomenon. This flux enables penetrate fully centre superconductor, resulting...