Skip navigation Accessibility information

Boron ( B )

Material Information

Buy Boron on-line

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

Choose a form to search our on-line catalogue  
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 Microfoil Monofilament Powder Rod Sputtering Target
Foil Granule Microfoil Monofilament Powder Rod Sputtering Target

Choose a form to search our on-line catalogue  

Index