Practical Magnesium Diboride (MgB2) Superconductor

The critical current density, jc, of high-pressure synthesized MgB2-based balk materials correlates with the amount and distribution of higher borides (MgB12) and Mg-B-O inclusions, which in tern correlates with the synthesis temperature and presence of additions (Ti, Ta, SiC). High-pressure-synthesized materials with near MgB12 composition of matrix exhibited superconducting transition temperature, Tc, of about 37 K, rather high jc (5∙105 and 103 A/cm2 in 0 T and 3.5 T, respectively, at 20 K) and doubled matrix microhardness: 25±1.1 GPa at 4.9 N –load as compared to materials with MgB2).

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Homogeneous carbon doping of magnesium diboride by high-temperature, high-pressure synthesis

Applied Physics Letters ◽

10.1063/1.4871578 ◽

2014 ◽

Vol 104 (16) ◽

pp. 162603 ◽

Cited By ~ 15

Author(s):

M. A. Susner ◽

S. D. Bohnenstiehl ◽

S. A. Dregia ◽

M. D. Sumption ◽

Y. Yang ◽

...

Keyword(s):

High Pressure ◽

High Temperature ◽

Magnesium Diboride ◽

Carbon Doping ◽

High Pressure Synthesis ◽

Pressure Synthesis ◽

High Temperature High Pressure

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Critical Comment on “Numerical solution of Bloch–Gruneisen function to determine the contribution of electron–phonon interaction in polycrystalline MgB2 superconductor” by Intikhab A. Ansari [Physica C: Superconductors, 470 (2010) 508–510]

Physica C Superconductivity ◽

10.1016/j.physc.2010.08.009 ◽

2010 ◽

Vol 470 (22) ◽

pp. 2076-2077

Author(s):

B.A. Mamedov ◽

I.M. Askerov

Keyword(s):

Numerical Solution ◽

Critical Comment ◽

Mgb2 Superconductor ◽

Phonon Interaction ◽

Electron Phonon Interaction

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Graphene doping to enhance the flux pinning and supercurrent carrying ability of a magnesium diboride superconductor

Superconductor Science and Technology ◽

10.1088/0953-2048/23/8/085003 ◽

2010 ◽

Vol 23 (8) ◽

pp. 085003 ◽

Cited By ~ 36

Author(s):

X Xu ◽

S X Dou ◽

X L Wang ◽

J H Kim ◽

J A Stride ◽

...

Keyword(s):

Flux Pinning ◽

Magnesium Diboride ◽

Graphene Doping

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POINT-CONTACT SPECTROSCOPY OF MAGNESIUM DIBORIDE WITH DIFFERENT COUNTER-ELECTRODES

Modern Physics Letters B ◽

10.1142/s0217984903006505 ◽

2003 ◽

Vol 17 (27n28) ◽

pp. 1405-1416

Author(s):

A. I. D'YACHENKO ◽

V. YU. TARENKOV ◽

M. A. BELOGOLOVSKII ◽

V. N. VARYUKHIN ◽

A. V. ABAL'OSHEV ◽

...

Keyword(s):

Andreev Reflection ◽

Magnesium Diboride ◽

Three Dimensional ◽

Point Contact ◽

Band Model ◽

Counter Electrodes ◽

Break Junctions ◽

Point Contact Spectroscopy ◽

Dc Current ◽

Two Band Model

We report on tunneling and Andreev-reflection conductance spectra of 39 K superconducting magnesium diboride, obtained with Pb and Au counter-electrodes. Two distinct steps at close to 2.7 and 7.1 meV appear in a low-resistance metallic-type Au–MgB 2 junction characteristic, whereas a tunneling-like spectrum measured for the same junction, annealed by the application of DC current, exhibits only a rounded contribution of the larger gap. Junctions with a superconducting lead counter-electrode pressed into a bulk MgB 2 sample reveal two conductance peaks that are interpreted as the result of the formation of a highly-transmitting break junctions inside the magnesium diboride ceramic. Our results strongly support the two-band model with two different gap values on quasi-two-dimensional σ (7.1 meV) and three-dimensional π (2.7 meV) Fermi surface sheets of MgB 2.

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