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Holmium ( Ho )

Material Information

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General Description:  

Discovered in 1878 by P.T. Cleve in Uppsala, Sweden, and independently in Geneva by M. Delafontaine and J-L Soret.

Holmium is a member of the lanthanide group and whose properties closely resemble those of erbium and dysprosium. It has an abundance of 1.4 ppm in the earth's crust. It is soft and malleable and is slowly attacked by oxygen and water. It is soluble in acids.

Applications for holmium are limited, but it is used as a flux concentrator in magnetic fields and also as a poison in nuclear reactors where it assists in keeping the chain reaction under control.
   

Atomic Properties

Atomic number 67
Atomic radius - Goldschmidt ( nm ) 0.176
Atomic weight ( amu ) 164.9304
Crystal structure Hexagonal close packed
Electronic structure Xe 4f11 6s2
Ionization potential No. eV
1 6.02
2 11.80
Natural isotope distribution Mass No. %
165 100
Thermal neutron absorption cross-section ( Barns ) 65
Valences shown 3

Electrical Properties

Electrical resistivity @20C ( µOhmcm ) 94
Temperature coefficient @0-100C ( K-1 ) 0.00171

Mechanical Properties

Material condition Polycrystalline
Bulk modulus ( GPa ) 40.5
Hardness - Vickers 60
Poisson's ratio 0.225
Tensile modulus ( GPa ) 66.9
Tensile strength ( MPa ) 262
Yield strength ( MPa ) 221

Physical Properties

Boiling point ( C ) 2695
Density @20C ( g cm-3 ) 8.803
Melting point ( C ) 1474

Thermal Properties

Coefficient of thermal expansion @0-400C ( x10-6 K-1 ) 9.5
Latent heat of evaporation ( J g-1 ) 1695
Latent heat of fusion ( J g-1 ) 104
Specific heat @25C ( J K-1 kg-1 ) 165
Thermal conductivity @0-100C ( W m-1 K-1 ) 16.2
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 Holmium on-line

Standard products are available in these forms
Foil Lump Powder Rod Wire
Foil Lump Powder Rod Wire

Choose a form to search our on-line catalog  

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