In-field Jc improvement by oxygen-free pyrene gas diffusion into highly dense MgB2 superconductor

Abstract

In-field Jc improvement by oxygen-free pyrene gas diffusion into highly dense In-field Jc improvement by oxygen-free pyrene gas diffusion into highly dense MgB2 superconductor MgB2 superconductor

Evidence of Point Pinning Centers in Un-Doped Mgb2 Wires at 20 K after HIP Process

“…This suggests that the starting composition of the material may influence B c2 . The results in Figure 6a show that 1 GPa pressure can increase B irr from 10 K to 27 K, and slightly reduce B irr above 27 K. By contrast, an increase in annealing temperature (Figure 6b) reduces B irr in between 15 K to 25 K and does not change B irr from 10 K to 15 K and above 25 K. Maeda and Susner claim that the value of the B irr is dependent on dislocation [28,29]. Moreover, Serquis showed that the HIP process can increase the density of dislocations [13].…”

Optimization of sintering conditions in bulk MgB2 material for improvement of critical current density

“…It is noticeable that the J c value of the samples heat-treated for 0.1 h at 1100 C and 6 h at 770 C approached the value of 14 A/cm 2 at 3.5 T, 20 K [24]. Pyrene lumps as carbon source were also used to improve critical current density of MgB 2 material and it was found that oxygen free pyrene gas diffusion into the bulk resulted in a self field J c at 20 K being dramatically improved to around 10 6 A/cm 2 [25]. The production of bulk MgB 2 material via reaction of MgB 4 and Mg was shown to be promising.…”

Control of core structure in MgB2 wire through tailoring boron powder

“…The size of starting powders is also important for increasing the mass density and thus decreasing the void size in MgB 2 tapes, which may lead to the improvement of the critical current density [21]. A different way to achieve this was recently found to be carbon doping, which is introduced by liquid mixing or gaseous phase diffusion for homogeneous carbon incorporation into MgB 2 [13,22]. The doping process provides carbon encapsulated boron, preventing boron agglomeration and decreasing the void density as well as the void size, as confirmed by a quantitative analysis of pores using X-ray tomography [13].…”