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    Boron ( B )

    Material Information

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    We stock and supply the following standard forms:
    Foil Granule Monofilament Powder Rod Sputtering Target
    Foil Granule Monofilament Powder Rod Sputtering Target

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    General Description:  

    Discovered in 1808 by L.J. Lussac and L.J. Thenard (in Paris) and Sir Humphrey Davy (in London).

    Boron is a non-metallic element which occurs in several allotropes. It is rarely found in nature, normally occurring as borates or orthoboric acid (the abundance of boron in the earth's crust is 10 ppm, the principal ore being borax, Na2B4O7.xH2O). Amorphous boron is the more common allotrope and exists as a dark powder which is unreactive towards water, oxygen, acids and alkalis. Boron finds importance within nuclear reactors due to its neutron absorbing capabilities, boron steel being used as control rod material. Boron compounds are used for a number of applications including the manufacture of certain grades of glass and detergents.

    Boron will react directly with most metals to produce metal borides which are hard, inert binary compounds of various formulae and arrangements of the boron atoms. For example, as single atoms (M2B), pairs (M3B2), single and double chains (MB, M3B4), sheets (MB2), B6 octahedra (MB6) and B12 clusters (MB12). Boron also forms the binary compound, boron nitride, which is of interest as it is isoelectronic with carbon and occurs in two structural modifications; one is a layer structure similar to graphite which is soft and lubricating, whilst the other (formed under high pressure) has a very hard, stable, tetrahedral structure as found in diamond.

       

    Atomic Properties

    Atomic number 5
    Atomic radius - Goldschmidt ( nm ) 0.097
    Atomic weight ( amu ) 10.81
    Crystal structure Tetragonal
    Electronic structure He 2s2 2p1
    Ionisation potential No. eV
    1 8.30
    2 25.2
    3 37.9
    4 259
    5 340
    Natural isotope distribution Mass No. %
    10 19.8
    11 80.2
    Photo-electric work function ( eV ) 4.5
    Thermal neutron absorption cross-section ( Barns ) 672
    Valences shown 3

    Electrical Properties

    Electrical resistivity @27C ( µOhmcm ) 1.8x1012

    Mechanical Properties

    Material condition Arc melted
    Hardness - Mohs 9.5
    Tensile modulus ( GPa ) 441
    Tensile strength ( MPa ) 1580-2410

    Physical Properties

    Boiling point ( C ) 3700
    Density @20C ( g cm-3 ) 2.34-2.37
    Melting point ( C ) 2180

    Thermal Properties

    Coefficient of thermal expansion @0-100C ( x10-6 K-1 ) 8.3
    Latent heat of evaporation ( J g-1 ) 35000
    Latent heat of fusion ( J g-1 ) 2090
    Specific heat @25C ( J K-1 kg-1 ) 1030

    Buy Boron on-line

    We stock and supply the following standard forms:
    Foil Granule Monofilament Powder Rod Sputtering Target
    Foil Granule Monofilament Powder Rod Sputtering Target

    Choose a form to search our on-line catalogue  

    Index