Development in processing of MgB2 cryo-magnet superconductors

Abstract

Articles you may be interested inDependence of magnetoelectric properties on sintering temperature for nano-SiC-doped MgB2/Fe wires made by combined in situ/ex situ process J. Appl. Phys. 111, 07E135 (2012); 10.1063/1.3677660 Transport properties of superconducting MgB2 composites with carbon-encapsulated Fe nanospheresSpark Plasma Sintering is a promising rapid consolidation technique that allows a better understanding and manipulating of sintering kinetics and therefore makes it possible to obtain MgB 2 -based ceramics with tailored microstructures. Commercial MgB 2 powders were spark plasma sintered with an applied mechanical pressure, leading to MgB 2 pellets with 99% relative density. The obtained samples show a sharp superconducting transition with an onset at 38.5 K. The critical current density was measured equal to 5.6 Â 10 4 A/cm 2 at 20 K under 1 T applied field. Otherwise, the trapped field was also investigated. A 5 mm thick pellet with a 20 mm diameter prepared with optimized processing temperature demonstrated a trapped field of 1.2 T at 15 K and up to 2.5 T at 10 K. V C 2014 AIP Publishing LLC. [http://dx.

Analysis of the microstructure of bulk MgB2 using TEM, EBSD and t‐EBSD

“…Xray diffraction analysis revealed additional peaks of the MgB 4 phase as it was expected for this temperature. More details about these samples can be found elsewhere (Noudem et al, 2014).…”

Critical current densities in Ag-added bulk MgB2

“…Ominous progress has been made in the development of MgB 2 materials processing, characterization, and applications [1,6]. The superconducting transition temperature of MgB 2 is significantly lower than that of YBa 2 Cu 3 O y "Y-123", instead, MgB 2 benefits from BCS-like superconducting features a large coherence length which allows a better Josephson junction fabrication.…”

Comparison of Temperature and Field Dependencies of the Critical Current Densities of Bulk YBCO, MgB<inline-formula> <tex-math notation="LaTeX">$_2$</tex-math> </inline-formula>, and Iron-Based Superconductors

“…For the application as superconducting permanent magnets, dubbed supermagnets or trapped field (TF) magnets, there are three different candidate materials available: (i) bulk, melttextured single crystalline materials of YBa 2 Cu 3 O x (YBCO or RE-123, where RE indicates rare-earths) [3], [4], and a superconducting YBCO foam [5] prepared in two different ways [6], [7] and (iii) bulk, polycrystalline iron-based superconductors (IBS) of Ba 0.6 K 0.4 Fe 2 As 2 (122) [8], [9] and FeSe with addition of Ag [10], [11] were chosen for comparison. The latter two types of material offer a much easier (and hence, cheaper) way of producing the samples as the grain boundaries (GBs) were found not to be weak-links, but do provide flux pinning like in the case of conventional superconductors like NbTi or Nb 3 Sn.…”

“…For the RE-123 materials, we have chosen a bulk YBCO sample [15] prepared via the infiltration-growth (IG) process [16], [17], a strut of a YBCO foam due to its outstanding pinning properties [5], [18], [19], and a (Nd,Eu,Gd)-123 (NEG) melt-textured bulk with TiO 2 -nanoparticles enhancing the flux pinning properties [20], [21]. For MgB 2 , we selected a sample prepared via solid-state sintering [6], a spark-plasma sintered sample [7], [22] and a sintered sample with added carbon-encapsulated boron [23], [24]. Finally, for the IBS, we selected sintered FeSe with 4 wt.-% Ag [11], [25] and we took data of hot-isostatic processed (HIP) 122 sample from Weiss et al [8], [9], where already data of TF measurements were published.…”