History and Production
The name is given after a village in Sweden, Ytterby. Discovered by J.C.G. de Marignac in 1878 from erbia earth (a mixture of rare earths oxides such as holmium, erbium etc.). In 1907, G. Urbain and independently C.A. von Welsbach showed that Marignac's sample was in fact a concentrate mixture of ytterbium and lutetium.
It is now recover commercially from monazite which contains about 0.03% of the metal. Ion-exchange and solvent extraction techniques are used to isolate the salts from other rare earths. The metal itself can be obtained by the reduction of oxide (Yb2O3) with lanthanum metal and then follow by distillation.
At the moment, there is no major commercial use of the metal. It has possible use to improve mechanical properties of stainless steel and as a radiation source for portable X-ray machine.
It is a silvery white, malleable and ductile metal. It reacts slowly with water. At room temperature, the metal exists in b form with a face centered packing structure. The metal is usually associated with other rare eraths in minerals such as monazite, xenotime and euxenite. Its natural abundance is about 3.1 ppm of the earth's crust.
Interatomic distance: 388 pm
Melting point: 819°C
Boiling point: 1196°C
Thermal conductivity/Wm-1K-1: 34.9 (27°C)
Density/kgm-3: 6965 (b, 25°C)
Standard Thermodynamic Data (atomic gas)
Enthalpy of formation: 152.3 kJ/mol
Gibbs free energy of formation: 118.4 kJ/mol
Entropy: 173.1 J/mol K
Heat capacity: 20.8 J/mol K
Electronic configuration: [Xe] 4f14 6s2
Term symbol: 1S0
Electron affinity: -1.930 kJ/mol Electronegativity (Pauline): -
Ionization energy (first, second, third): 603.435, 1174.82, 2416.96 kJ/mol