Enhanced critical current density in MgB<sub>2</sub> prepared by reaction of MgB<sub>4</sub> and Mg

Tan, K. L.; Lim, Kean Pah; Halim, Abdul; Chen, Soo Kien

doi:10.1002/pssa.201228752

Cited by 7 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The detailed preparation condition of MgB 4 was well described in previous reports [33][34][35][36][37][38]. The impurity phases included in the synthesized MgB 4 powder were removed by the HNO 3 leaching process [36].…”

Section: Enhanced Critical Current Density Of In Situ Processed Mgb 2mentioning

confidence: 99%

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions

S.H.Kim¹,

Kang²,

Jun³

et al. 2017

Progress in Superconductivity and Cryogenics

View full text Add to dashboard Cite

The effects of MgB 4 addition on the superconducting properties and the microstructure of in situ processed MgB 2 bulk superconductors were studied. MgB 4 powder of 1-20 wt.% was mixed with (Mg + 2B) powder and then pressed into pellets. The pellets of (Mg + 2B + xMgB 4 ) were heat-treated at 650 ℃ for 1 h in flowing argon. The powder X-ray diffraction (XRD) analysis for the heat-treated samples showed that the major formed phase in all samples was MgB 2 and the minor phases were MgB 4 and MgO. The full width at half maximum (FWHM) values showed that the grain size of MgB 2 decreased as the amount of MgB 4 addition increased. MgB 4 particles included in a MgB 2 matrix is considered to suppress the grain growth of MgB 2 . The onset temperatures (T c,onset ) of MgB 2 with MgB 4 addition (0-10 wt.%) was between 37-38 K. The 20 wt.% MgB 4 addition slightly reduced the T c,onset of MgB 2 to 36.5 K. This result indicates that MgB 4 addition did not influence the superconducting transition temperature (T c ) of MgB 2 significantly. On the other hand, the small additions of 1-5 wt.% MgB 4 increased the critical current density (J c ) of MgB 2 . The J c enhancement by MgB 4 addition is attributed not only to the grain size refinement but also to the possible flux pinning of MgB 4 particles dispersed in a MgB 2 matrix.

show abstract

Section: Enhanced Critical Current Density Of In Situ Processed Mgb 2mentioning

confidence: 99%

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions

S.H.Kim¹,

Kang²,

Jun³

et al. 2017

Progress in Superconductivity and Cryogenics

View full text Add to dashboard Cite

show abstract

“…22 On the other hand, there are many attempts to remove the EPR inactive MgO from MgB 2 material; however, these methods only reached success for a certain amount of reduction of MgO. [23][24][25] In our preparation route, it is also not possible to remove MgO completely by annealing.…”

mentioning

confidence: 99%

Defect structure of ultrafine MgB2 nanoparticles

Bateni

Repp

Thomann

et al. 2014

Applied Physics Letters

View full text Add to dashboard Cite

Defect structure of MgB2 bulk and ultrafine particles, synthesized by solid state reaction route, have been investigated mainly by the aid of X-band electron paramagnetic resonance spectrometer. Two different amorphous Boron (B) precursors were used for the synthesis of MgB2, namely, boron 95 (purity 95%–97%, <1.5 μm) and nanoboron (purity >98.5%, <250 nm), which revealed bulk and nanosized MgB2, respectively. Scanning and transmission electron microscopy analysis demonstrate uniform and ultrafine morphology for nanosized MgB2 in comparison with bulk MgB2. Powder X-ray diffraction data show that the concentration of the by-product MgO is significantly reduced when nanoboron is employed as precursor. It is observed that a significant average particle size reduction for MgB2 can be achieved only by using B particles of micron or nano size. The origin and the role of defect centers were also investigated and the results proved that at nanoscale MgB2 material contains Mg vacancies. Such vacancies influence the connectivity and the conductivity properties which are crucial for the superconductivity applications.

show abstract

“…For ex situ MgB 2 added with Mg, samples were prepared according to the stoichiometry of MgB 2 ? 0.5 Mg [22]. For this set of samples, we chose 700 °C and 1000 °C as the lower and upper bound temperatures according to the work reported in [14] with a shorter sintering time of 1, 3, and 7 h. The sintering temperature and sintering time were varied in order to find the optimum condition for improving the grain connectivity, hence the J c of the samples.…”

Section: Introductionmentioning

confidence: 99%

Enhanced critical current density of ex situ MgB2 via control of Mg assisted sintering

Hapipi

Chen

Shaari

et al. 2022

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

In this work, ex situ MgB2 was mixed with 0.5 mol of Mg and sintered. The sintering conditions were varied over a temperature range of 600–1000 °C for 1, 3, and 7 h, respectively. The addition of Mg during the sintering increased the partial pressure of Mg and thus suppressed the decomposition of MgB2. Onset of critical temperature, Tc, was retained at ∼ 38 K even after the addition of Mg. By increasing the sintering temperature, magnetic critical current density, Jc at self-field, and 20 K of the ex situ samples increased consistently. With the addition of Mg for 1 h sintering, self-field Jc (20 K) was enhanced more than 20 times to 104 A cm−2 as the sintering temperature was increased. Such significant enhancement in the Jc is mainly due to the improved grain coupling aided by Mg during the short sintering.

show abstract

Enhanced critical current density in MgB₂ prepared by reaction of MgB₄ and Mg

Cited by 7 publications

References 34 publications

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions

Defect structure of ultrafine MgB2 nanoparticles

Enhanced critical current density of ex situ MgB2 via control of Mg assisted sintering

Contact Info

Product

Resources

About

Enhanced critical current density in MgB2 prepared by reaction of MgB4 and Mg

Cited by 7 publications

References 34 publications

Enhanced critical current density of in situ processed MgB2 bulk superconductors with MgB4 additions

Enhanced critical current density of in situ processed MgB2 bulk superconductors with MgB4 additions

Defect structure of ultrafine MgB2 nanoparticles

Enhanced critical current density of ex situ MgB2 via control of Mg assisted sintering

Contact Info

Product

Resources

About

Enhanced critical current density in MgB₂ prepared by reaction of MgB₄ and Mg

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions

Enhanced critical current density of in situ processed MgB₂ bulk superconductors with MgB₄ additions