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Iridium ( Ir )

Material Information

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Foil Lump Microfoil Powder Rod Sputtering Target Wire
Foil Lump Microfoil Powder Rod Sputtering Target Wire

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General Description:  

Discovered in 1803 in London by S. Tennant.

Iridium is a rare, precious metal which is hard, brittle and has a low ductility, which makes it a difficult material to work. In appearance, it is a lustrous, silvery metal. It has an abundance in the earth's crust of approximately 3x10 6 ppm.

As might be expected from its position in the periodic table, iridium is stable to air and water and is not attacked by any acids, including "aqua regia" (this acid is used to separate iridium from the other platinum group metals). However, fused NaOH will attack iridium. It is extremely corrosion resistant and is used as an alloying agent with metals such as gold and osmium to produce alloys which are extremely hard and have good corrosion resistance. Iridium is also used in spark plugs, and its radioactive isotope, €92Ir is a medium energy gamma emitter used for industrial radiography.

   

Atomic Properties

Atomic number 77
Atomic radius - Goldschmidt ( nm ) 0.135
Atomic weight ( amu ) 192.22
Crystal structure Face centred cubic
Electronic structure Xe 4f14 5d7 6s2
Ionization potential No. eV
1 9.1
Natural isotope distribution Mass No. %
191 37.3
193 62.7
Photo-electric work function ( eV ) 4.6
Thermal neutron absorption cross-section ( Barns ) 425
Valences shown 3, 4

Electrical Properties

Electrical resistivity @20C ( µOhmcm ) 5.1
Temperature coefficient @0-100C ( K-1 ) 0.0045
Superconductivity critical temperature ( K ) 0.11
Thermal emf against Pt (cold 0C - hot 100C) ( mV ) +0.65

Mechanical Properties

Material condition Soft Hard Polycrystalline
Bulk modulus ( GPa )     371
Hardness - Vickers 200-300 650
Poisson's ratio     0.26
Tensile modulus ( GPa )     528
Tensile strength ( MPa ) 550-1100 1200

Physical Properties

Boiling point ( C ) 4130
Density @20C ( g cm-3 ) 22.4
Melting point ( C ) 2410

Thermal Properties

Coefficient of thermal expansion @0-100C ( x10-6 K-1 ) 6.8
Latent heat of evaporation ( J g-1 ) 3186
Latent heat of fusion ( J g-1 ) 135
Specific heat @25C ( J K-1 kg-1 ) 133
Thermal conductivity @0-100C ( W m-1 K-1 ) 147
All information and technical data are given as a guide only. Although every effort has been made to ensure that the information is correct, no warranty is given as to its completeness or accuracy.

Buy Iridium on-line

We stock and supply the following standard forms:
Foil Lump Microfoil Powder Rod Sputtering Target Wire
Foil Lump Microfoil Powder Rod Sputtering Target Wire

Choose a form to search our on-line catalog  

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