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Your current location :Home > Magnesium diboride - MgB2

Magnesium Diboride - MgB2

Aluminum Diboride - AlB2

Magnesium diboride (MgB2) is a simple ionic binary compound that has proven to be an inexpensive and useful superconducting material.
Magnesium diboride can be synthesized by several routes. The simplest is by high temperature reaction between boron and magnesium powders. Formation begins at 650 °C; however, since magnesium metal melts at 652 °C, the reaction mechanism is considered to be moderated by magnesium vapor diffusion across boron grain boundaries. At conventional reaction temperatures, sintering is minimal, although enough grain recrystallization occurs to permit Josephson qu
Properties depend greatly on composition and fabrication process. Many properties are anisotropic due to the layered structure. 'Dirty' samples, e.g., with oxides at the crystal boundaries, are different from 'clean' samples.

Basic Information

CAS Number:12007-25-9

ChemSpider:13118398
ECHA InfoCard:100.031.352
PubChem:15987061
Chemical formula:MgB2
Molar mass:45.93 g/mol

    Density:2.57 g/cm3
    Melting point:830 °C (1,530 °F; 1,100 K) (decomposes)
    Crystal structure:Hexagonal, hP3
    Space group:P6/mmm, No. 191

Aluminum Diboride Sputtering Target - AlB2 Target

Purity--- 99.9%

Shape---Discs, Plate, Step (Dia ≤480mm, Thickness ≥1mm)

Rectangle, Sheet, Step (Length ≤420mm, Width ≤270mm, Thickness ≥1mm)

Tube( Diameter< 300mm, Thickness >2mm ) 

Application - Coating for thin film, Chromium(III) boride is an inorganic compound with the chemical formula CrB. It is used in wear resistant coatings.

Aluminum Diboride Evaporation Material - AlB2 Granule

Purity - 99.9%

Granule - 3-6mm, 1-6mm

Application - Coating for thin film

Aluminum Diboride Powder - AlB2

Purity--- 99.9%

Granularity --- 100mesh、200 mesh、325mesh

Aluminum Boron  Alloy  - AlB

Purity--- AlB 97/3 (B%2-4%),  AlB 95/5 (B% 4%-6%), AlB 90/10(B% 8-13%), AlB 85/18(B% 13-18%)

Shape---ingot, Lumps, Powders

Relation Products:

Boron sputtering targets - B;

Boron carbide sputtering target - B4C;

Boron Nitride sputtering target - BN;

Aluminium Diboride Sputtering target - AlB2;

Cerium Hexaboride sputtering targets - CeB6;

Chrominium Boride sputtering targets - CrB;

Cobalt Boride sputtering target - CoB;

Hafnium Diboride (HfB2) Sputtering Target - HfB2;

Iron Boride sputtering targets - FeB;

Lathanum Hexaboride sputtering targets - LaB6;

Magnesium Diboride sputtering targets - MgB2;

Molybdenum Diboride sputtering targets - MoB2;

Neodymium Boride (NdB) Sputtering Target;

Nickel Boride sputtering targets -Ni2B;

Niobium Diboride (NbB2) Sputtering target - NbB2;

Tantalum Diboride Sputterng target - TaB2;

Titanium Aluminum Boron Sputtering Targets - TiAlB;

Titanium Diboride sputtering targets - TiB2;

Tungsten Diboride Sputtering tarets - WB2;

Vanadium Boride (VB2) Sputtering Target - VB / VB2;

Zirconium Diboride Sputtering targets - ZrB2;

Other information

Magnesium diboride (MgB2) is a simple ionic binary compound that has proven to be an inexpensive and useful superconducting material.
Magnesium diboride can be synthesized by several routes. The simplest is by high temperature reaction between boron and magnesium powders. Formation begins at 650 °C; however, since magnesium metal melts at 652 °C, the reaction mechanism is considered to be moderated by magnesium vapor diffusion across boron grain boundaries. At conventional reaction temperatures, sintering is minimal, although enough grain recrystallization occurs to permit Josephson qu
Properties depend greatly on composition and fabrication process. Many properties are anisotropic due to the layered structure. 'Dirty' samples, e.g., with oxides at the crystal boundaries, are different from 'clean' samples.
The highest superconducting transition temperature Tc is 39 K.
MgB2 is a type-II superconductor, i.e. increasing magnetic field gradually penetrates into it.
Maximum critical current (Jc) is: 105 A/m2 at 20 T, 106 A/m2 at 18 T, 107 A/m2 at 15 T, 108 A/m2 at 10 T, 109 A/m2 at 5 T.
As of 2008 : Upper critical field (Hc2): (parallel to ab planes) is ~14.8 T, (perpendicular to ab planes) ~3.3 T, in thin films up to 74 T, in fibers up to 55 T.
Improvement by doping
Various means of doping MgB2 with carbon (e.g. using 10% malic acid) can improve the upper critical field and the maximum current density[11][12] (also with polyvinyl acetate ).

5% doping with carbon can raise Hc2 from 16 T to 36 T whilst lowering Tc only from 39 K to 34 K. The maximum critical current (Jc) is reduced, but doping with TiB2 can reduce the decrease.[14] (Doping MgB2 with Ti is patented. )

The maximum critical current (Jc) in magnetic field is enhanced greatly (approx double at 4.2 K) by doping with ZrB2.
Even small amounts of doping lead both bands into the type II regime and so no semi-Meissner state may be expected.antum tunnelling between grains.

MgB2 is a multi-band superconductor, that is each Fermi surface has different superconducting energy gap. For MgB2, sigma bond of boron is strong, and it induces large s-wave superconducting gap, and pi bond is weak and induces small s-wave gap. The quasiparticle states of the vortices of large gap are highly confined to the vortex core. On the other hand, the quasiparticle states of small gap are loosely bound to the vortex core. Thus they can be delocalized and overlap easily between adjacent vortices. Such delocalization can strongly contribute to the thermal conductivity, which shows abrupt increase above Hc1.

 

 

 

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