The discrepancies in different facets of MgB2 bulk superconductors prepared under various sintering durations by spark plasma sintering

In this study, high-density magnesium diboride (MgB2) bulk superconductors were synthesized by spark plasma sintering (SPS) under pressure to improve the field dependence of the critical current density (Jc-B) in MgB2 bulk superconductors. We investigated the relationship between sintering conditions (temperature and time) and Jc-B using two methods, ex situ (sintering MgB2 synthesized powder) and in situ (reaction sintering of Mg and B powder), respectively. As a result, we found that higher density with suppressed particle growth and suppression of the formation of coarse particles of MgB4 and MgO were found to be effective in improving the Jc-B characteristics. In the ex situ method, the degradation of MgB2 due to pyrolysis was more severe at temperatures higher than 850 °C. The sample that underwent SPS treatment for a short time at 850 °C showed higher density and less impurity phase in the bulk, which improved the Jc-B properties. In addition, the in situ method showed very minimal impurity with a corresponding improvement in density and Jc-B characteristics for the sample optimized at 750 °C. Microstructural characterization and flux pinning (fP) analysis revealed the possibility of refined MgO inclusions and MgB4 phase as new pinning centers, which greatly contributed to the Jc-B properties. The contributions of the sintering conditions on fP for both synthesis methods were analyzed.

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Superconducting Properties of MgB2 Bulk Shaped by Spark Plasma Sintering

Materials Today Proceedings ◽

10.1016/j.matpr.2016.01.088 ◽

2016 ◽

Vol 3 (2) ◽

pp. 545-549 ◽

Cited By ~ 5

Author(s):

J.G. Noudem ◽

L. Dupont ◽

L. Gozzelino ◽

P. Bernstein

Keyword(s):

Spark Plasma Sintering ◽

Superconducting Properties ◽

Mgb2 Bulk ◽

Plasma Sintering ◽

Spark Plasma

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Mechanical Properties of MgB2 Bulk Fabricated by Spark Plasma Sintering

Physics Procedia ◽

10.1016/j.phpro.2015.05.128 ◽

2015 ◽

Vol 65 ◽

pp. 77-80 ◽

Cited By ~ 5

Author(s):

A. Murakami ◽

J. Noudem ◽

Z. Guesmi ◽

T. Kudo ◽

A. Iwamoto

Keyword(s):

Mechanical Properties ◽

Spark Plasma Sintering ◽

Mgb2 Bulk ◽

Plasma Sintering ◽

Spark Plasma

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Properties of ex-situ MgB2 bulk samples prepared by uniaxial hot pressing and spark plasma sintering

Physica C Superconductivity ◽

10.1016/j.physc.2018.05.008 ◽

2018 ◽

Vol 551 ◽

pp. 48-54 ◽

Cited By ~ 5

Author(s):

W. Häßler ◽

J. Scheiter ◽

P. Hädrich ◽

S. Kauffmann-Weiß ◽

B. Holzapfel ◽

...

Keyword(s):

Spark Plasma Sintering ◽

Hot Pressing ◽

Ex Situ ◽

Mgb2 Bulk ◽

Plasma Sintering ◽

Spark Plasma

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Bulk superconductors textured and densified by Spark Plasma Sintering

MRS Proceedings ◽

10.1557/opl.2015.675 ◽

2015 ◽

Vol 1807 ◽

pp. 7-10 ◽

Cited By ~ 1

Author(s):

J. G. Noudem ◽

L. Dupont ◽

P. Bernstein

Keyword(s):

Spark Plasma Sintering ◽

Crystallographic Orientation ◽

Magnetic Levitation ◽

Bulk Material ◽

Field Measurements ◽

Force Measurements ◽

Bulk Superconductors ◽

Plasma Sintering ◽

Spark Plasma ◽

The One

ABSTRACTIn this contribution, we report progress in the preparation of superconducting materials made by Spark Plasma Sintering (SPS). On the one hand, the fabrication process was optimized in order to improve the texturing of Bi2Ca2Sr2CuO8 superconductor ceramics. The new process is referred to as “Spark Plasma Texturing” (SPT). During SPT, the bulk material is free to deform itself. As a result, an inter-grain preferential crystallographic orientation is generated, while materials processed by conventional SPS are usually quasi-isotropic. The crystallographic orientation causes a strong anisotropy in the magnetic properties of the Bi2Ca2Sr2CuO8 bulk.On the other hand, superconducting MgB2 discs were consolidated using the rapid SPS process. MgB2 has not been yet been seriously considered as a superconductor that could be used for magnetic levitation. Here we present trapped field measurements as a function of the distance to the superconductor and field cooled levitation force measurements that suggests that it presents interesting characteristics for this application.

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