Enhancement of critical current density in (Ba,Na)Fe2As2 round wires using high-pressure sintering

We report the property studies of a MgB2 superconductor with high critical current density. The MgB2 superconductor was readily fabricated through a direct high-pressure synthesis of the respective elements. The obtained high-density MgB2 undergoes a sharp superconducting transition at 39 K. The bulk critical current density (Jc) of the sample was calculated on the basis of Bean's critical state model, and rather high critical current densities over a wide temperature range were obtained in comparison with the ambient prepared samples. The results highlight that high-pressure sintering would be a promising way to produce and search for this kind of intermetallic boride and the related superconductors.

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Effects of High-Pressure Sintering on Critical Current Density in (Ba,K)Fe2As2 PIT Wires

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2014.2381554 ◽

2015 ◽

Vol 25 (3) ◽

pp. 1-4 ◽

Cited By ~ 9

Author(s):

T. Tamegai ◽

S. Pyon ◽

Y. Tsuchiya ◽

H. Inoue ◽

N. Koizumi ◽

...

Keyword(s):

High Pressure ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

High Pressure Sintering

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Effects of high-pressure annealing on critical current density in 1 2 2 type iron pnictide wires

Physica C Superconductivity ◽

10.1016/j.physc.2014.03.008 ◽

2014 ◽

Vol 504 ◽

pp. 69-72 ◽

Cited By ~ 3

Author(s):

Sunseng Pyon ◽

Yuji Tsuchiya ◽

Hiroshi Inoue ◽

Norikiyo Koizumi ◽

Hideki Kajitani ◽

...

Keyword(s):

High Pressure ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Iron Pnictide

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Formation of Higher Borides During High-Pressure Synthesis and Sintering of Magnesium Diboride and Their Positive Effect on Pinning and Critical Current Density

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2009.2018151 ◽

2009 ◽

Vol 19 (3) ◽

pp. 2780-2783 ◽

Cited By ~ 14

Author(s):

T.A. Prikhna ◽

W. Gawalek ◽

Y.M. Savchuk ◽

A.V. Kozyrev ◽

M. Wendt ◽

...

Keyword(s):

High Pressure ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Magnesium Diboride ◽

High Pressure Synthesis ◽

Pressure Synthesis ◽

Positive Effect

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Self-Propagating High Temperature Synthesis of MgB2 Superconductor in High-Pressure of Argon Condition

Eurasian Chemico-Technological Journal ◽

10.18321/ectj649 ◽

2017 ◽

Vol 19 (2) ◽

pp. 177 ◽

Cited By ~ 1

Author(s):

S. Tolendiuly ◽

S. M. Fomenko ◽

G. C. Dannangoda ◽

K. S. Martirosyan

Keyword(s):

High Pressure ◽

High Temperature ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

High Pressures ◽

Volume Fraction ◽

Temperature Synthesis ◽

High Temperature Synthesis ◽

Ar Gas

Magnesium diboride can be synthesized under argon ambient, elevated or high pressures. High-pressure syntheses are promising methods for manufacturing of the bulk MgB2 superconductor material. We have been used high pressure of Ar gas in order to investigate its effect on properties of MgB2 superconductor such as critical temperature and current density. Bulk MgB2 superconductor was synthesized from elemental Mg–B powders in thermal explosion mode of self-propagating high-temperature synthesis (SHS) under argon pressure of 25 atm. XRD pattern of the as-synthesized product indicates an almost complete conversion of the reactants to the MgB2 single phase. Most of the diffractions peaks are related to the MgB2 polycrystalline bulk material. The impurity fraction is less than 24.3% in total sample and identified as MgO and MgB4 secondary phases. The positive effect of pressure of Ar gas during synthesis of MgB2 on critical current density JC has been confirmed. The critical current density of the sample was achieved in high pressure reactor was 3.8×106 A/cm2. A superconducting volume fraction of 16% under a magnetic field of 10 Oe was obtained at 5 K, indicating that the superconductivity was bulk in nature. The succeeded level of superconductor parameters of the high-pressure synthesized MgB2 and the possibility to produce a large bulk products make this technology very promising for practical applications.

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High-Pressure High-Temperature Synthesis of Nanostructural Magnesium Diboride for Electromotors and Devices Working at Liquid Hydrogen Temperatures

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.47.25 ◽

2006 ◽

Vol 47 ◽

pp. 25-30 ◽

Cited By ~ 4

Author(s):

Tatiana Prikhna ◽

Wolfgang Gawalek ◽

Yaroslav Savchuk ◽

Nina Sergienko ◽

Viktor Moshchil ◽

...

Keyword(s):

High Pressure ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

High Pressure Cell ◽

Ybco Bulk ◽

High Temperature Synthesis ◽

High Pressure High Temperature ◽

Impurity Hydrogen ◽

First Time

Addition of Ti and Zr to high-pressure (HP) synthesized MgB2 results in an increase of critical current density of the material due to the absorption of impurity hydrogen coming most likely from the materials of a high-pressure cell. The results of the studies of structure, critical current density, trapped field and mechanical characteristics are discussed. High-pressure synthesized MgB2 (with Ti additions) blocks were for the first time used in a SC electromotor at 20 K and demonstrated the efficiency similar to that of MT-YBCO bulk (at the same working temperature).

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The Effect of Oxygen Distribution Inhomogeneity and Presence of Higher Borides on the Critical Current Density Improvement of Nanostructural MgB2

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.75.161 ◽

2010 ◽

Vol 75 ◽

pp. 161-166 ◽

Cited By ~ 1

Author(s):

Tetiana Prikhna ◽

Wolfgang Gawalek ◽

Yaroslav Savchuk ◽

Maxim Serga ◽

Tobias Habisreuther ◽

...

Keyword(s):

High Pressure ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Upper Critical Field ◽

The Self ◽

Ex Situ ◽

Ac Losses ◽

Material Structure ◽

Effect Of Oxygen

MgB2-based nanostructural materials with rather high oxygen concentration (5-14 wt.%) and dispersed grains of higher borides (MgB12, MgB7) high-pressure (2 GPa or 30 MPa) synthesized (in-situ) or sintered (ex-situ) demonstrated high superconducting characteristics (critical current density, jc, up to 1.8-1.0106 A/cm2 in the self magnetic field and 103 in 8 T field at 20 K, 3-1.5105 A/cm2 in the self field at 35 K, upper critical field up to HC2 = 15 T at 22 K, field of irreversibility Hirr =13 T at 20 K). The additives (Ti, SiC) and synthesis or sintering temperature can affect the segregation of oxygen and formation of oxygen-enriched Mg-B-O inclusions in the material structure, thus reducing the amount of oxygen in the material matrix as well as the formation of higher borides grains, which affects an increase of the critical current density. The record high HC2 and Hirr have been registered for the material high-pressure (2 GPa) synthesized from Mg and B at 600 oC having 17% porosity and more than 7 wt.% of oxygen. The attained values of the critical current, AC losses and thermal conductivity make the materials promising for application for fault current limiters and electromotors. The structural and superconducting (SC) characteristics of the material with matrix close to MgB12 in stoichiometry has been studied and the SC transition Tc=37 K as well as jc= 5×104 A/cm2 at 20 K in the self field were registered, its Raman spectrum demonstrated metal-like behavior.

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