Lutetium

Name: Lutetium
Symbol: Lu
Atomic Number: 71
Mass fraction of the earth’s shell: 0,7 ppm
Melting Point: 1652 °C
Boiling Point: 3330 °C
Electrical Conductivity: 1,72 x 106 A·V−1·m−1

Name: Lutetium
Symbol: Lu
Atomic Number: 71
Mass fraction of the earth’s shell: 0,7 ppm
Melting Point: 1652 °C
Boiling Point: 3330 °C
Electrical Conductivity: 1,72 x 106 A·V−1·m−1

 

HISTORY

Geaorges Urbain
Georges Urbain (© CC BY 4.0 – Urbain Archives IBPC)

In 1907, lutetium was discovered, the penultimate lanthanoid to date. Although Georges Urbain, Carl Auer von Welsbach, and Charles James claimed the discovery for themselves, Urbain ultimately goes down in history as the discoverer of lutetium. The old name of Paris was the inspiration for the naming of the element.

Metallic lutetium was first produced in 1953. Until this year, lutetium was known as cassiopeium in German-speaking countries.

CHARACTERISTICS & EXTRACTION

Lutetium is a shiny silver heavy metal of superlatives: the element has the highest density, melting point, and boiling point of all rare earths. The production process is complex. First, the lutetium companions are separated. Hydrogen fluoride turns the oxide into lutetium fluoride. Metallic lutetium is produced by adding calcium to form calcium fluoride. Remelting in a vacuum ensures that any residual calcium and impurities are left behind. The silver-grey metal is very soft, easily ductile, and malleable. In dry air, lutetium hardly reacts; in moist air, it turns grey. At higher temperatures, it burns to the sesquioxide Lu2O3. If it comes into contact with water, hydroxide is formed.

Lutetium is used in scintillator crystals for positron emission tomography.

The economic importance of lutetium is low. In medicine, however, lutetium has various applications. For example, it is used in scintillator crystals for positron emission tomography. The radionuclide 177Lu can be used as a therapy against neuroendocrine tumours. One method of treating prostate carcinomas is irradiation with radioactive lutetium.