Magnesium Boride (MgB2)-Powder

Characteristic




Magnesium diboride is the inorganic compound with the formula MgB2. It is a dark gray, water-insoluble solid, The crystal structure belongs to hexagonal system.It is an intercalated compound with alternating layers of magnesium and boron.

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.




Chemical formula:MgB2

Density 2.57 g/cm3

Molar mass 45.93 g/mol

Crystal structure:Hexagonal, hP3

Melting point 830 °C (1,530 °F; 1,100 K) (decomposes)

Space group:P6/mmm, No. 191




Application




1.Superconductors

Superconducting properties and low cost make magnesium diboride attractive for a variety of applications. For those applications, MgB2 powder is compressed with silver metal (or 316 stainless steel) into wire and sometimes tape via the PIT process.




2.Propellants, explosives, pyrotechnics

Unlike elemental boron whose combustion is incomplete through the glassy oxide layered impeding oxygen diffusion, magnesium diboride burns completely when ignited in oxygen or in mixtures with oxidizers. Thus magnesium boride has been proposed as fuel in ram jets. In addition the use of MgB2 in blast-enhanced explosives and propellants has been proposed for the same reasons.