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

2006 ◽  
Vol 47 ◽  
pp. 25-30 ◽  
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).

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

2017 ◽  
Vol 19 (2) ◽  
pp. 177 ◽  
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

<p>Magnesium diboride can be synthesized under argon ambient, elevated or high pressures. High-pressure syntheses are promising methods for manufacturing of the bulk MgB<sub>2</sub> superconductor material. We have been used high pressure of Ar gas in order to investigate its effect on properties of MgB<sub>2</sub> superconductor such as critical temperature and current density. Bulk MgB<sub>2</sub> 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 MgB<sub>2</sub> single phase. Most of the diffractions peaks are related to the MgB<sub>2</sub> polycrystalline bulk material. The impurity fraction is less than 24.3% in total sample and identified as MgO and MgB<sub>4</sub> 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 3.8×10<sup>6</sup> A/cm<sup>2</sup>. 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 MgB<sub>2</sub> and the possibility to produce a large bulk products make this technology very promising for practical applications.</p>

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

2020 ◽  
Vol 33 (6) ◽  
pp. 065001 ◽  
Author(s):  
Sunseng Pyon ◽  
Daisuke Miyawaki ◽  
Tsuyoshi Tamegai ◽  
Satoshi Awaji ◽  
Hijiri Kito ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
High Pressure Sintering

YBCO Bulk Superconductors with Sm Addition

2017 ◽  
Vol 891 ◽  
pp. 483-488 ◽  
Author(s):  
Daniela Volochová ◽  
Vitaliy Antal ◽  
Jozef Kováč ◽  
Pavel Diko
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Properties ◽  
Ybco Bulk ◽  
Pinning Centers ◽  
Bulk Superconductors ◽  
Powder Addition ◽  
Current Densities ◽  
Precursor Powders

The influence of Sm addition on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied. Precursor powders YBa2Cu3O7-δ (Y-123), Y2O3 and CeO2 were enriched with different amounts of SmBa2Cu3Oy (Sm-123) or Sm2O3 powders with the aim to increase critical current density, Jc,by introducing additional pinning centers. YBCO bulk superconductors with SmBa2Cu3Oy (Y123-Sm) or Sm2O3 (Y123-SmO) powder addition were prepared by the optimized top seeded melt growth process in the form of single grains. Microstructure analysis revealed that Sm2O3 addition leads to a higher amount of smaller Y2BaCuO5 (Y-211) particles, what is related to high critical current densities (Jc ~ 7 x 104 A/cm2) of the YBCO samples with Sm2O3 addition in low magnetic fields. The effect of Sm addition in the form of SmBa2Cu3Oy as well as Sm2O3 powder on Y2BaCuO5 particle size, critical temperature, Tc, and critical current density, Jc, is reported.

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

2014 ◽  
Vol 504 ◽  
pp. 69-72 ◽  
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

Effects of high-pressure sintering on critical current density in Co-doped BaFe2As2 wires

2014 ◽  
Vol 504 ◽  
pp. 73-76 ◽  
Author(s):  
Hiroshi Inoue ◽  
Yuji Tsuchiya ◽  
Shinya Tada ◽  
Sunseng Pyon ◽  
Hideki Kajitani ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
High Pressure Sintering ◽  
Co Doped

Proton Irradiation Enhancement of Implanted Layers on Ceramic YBCO Bulk

1992 ◽  
Vol 275 ◽  
Author(s):  
D. Andreone ◽  
R. Cherubini ◽  
S. Colombo ◽  
R. Gerbaldo ◽  
E. Mezzetti ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Coupling Strength ◽  
Proton Irradiation ◽  
Relative Effect ◽  
Surface Layers ◽  
Ybco Bulk ◽  
Two Samples ◽  
Ceramic Ybco

ABSTRACTIn this work the possibility of enhancing the critical current density in proton implanted surface layers on YBCO bulk is discussed. A complete transport characterization shows that, for what concerns two samples from different irradiation runs, the critical current density has been enhanced. Increases of other meaningful parameters, such as average pinning energy and vortex-antivortex coupling strength, have also been found, although the relative effect of the implanted layer on the whole specimen cannot be evaluated in a fully quantitative way.

High Critical Current Density of a MgB2 Bulk Superconductor High-pressure Synthesized Directly from the Elements

2002 ◽  
Vol 17 (3) ◽  
pp. 525-527 ◽  
Author(s):  
C-Q. Jin ◽  
S-C. Li ◽  
J-L. Zhu ◽  
F-Y. Li ◽  
Z-X. Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Transition ◽  
High Critical Current Density ◽  
Bulk Superconductor ◽  
High Pressure Sintering ◽  
Current Densities ◽  
Pressure Synthesis

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.

scholarly journals A New Kinetics Defect Diffusion Model and the Critical Current Density of Semiconductor Laser Degradation

2016 ◽  
Vol 8 (4) ◽  
pp. 11
Author(s):  
Jack Jia-Sheng Huang ◽  
Yu-Heng Jan
Keyword(s):  
Critical Current Density ◽  
Semiconductor Laser ◽  
Critical Current ◽  
Diffusion Model ◽  
Current Density ◽  
Integrated Circuit ◽  
Failure Time ◽  
Defect Diffusion ◽  
Failure Time Distribution ◽  
First Time

<p class="1Body">Critical current density on the electromigration failure is a commonly observed phenomenon in the integrated circuit (IC) interconnect. The critical current density is important for the lognormal distribution and failure time extrapolation of IC metal conductors. In this paper, we report the critical current density (j<sub>c</sub>) of semiconductor laser degradation for the first time. Despite of the different physical origin, the j<sub>c</sub> of the laser degradation exhibits similar effect on the failure time distribution. We develop a new kinetic defect diffusion model that can account for the existence of j<sub>c</sub>. We discuss the physical mechanism and its implication in the reliability extrapolation of diode lasers.</p>

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