General information

Dysprosium (from Greek δυσπρόσιτος "inaccessible") is a chemical element with the element symbol Dy and the atomic number 66. In the periodic table, it is in the group of lanthanides and counts the French PE Lecoq de Boisbaudran the isolation of dysprosium oxide from a sample of holmium oxide, which had been thought to be a uniform substance until then. Since the chemical properties of lanthanides are very similar and they are always associated in nature, a distinction was only possible here with very complex analysis methods. Its contribution to the structure of the earth's crust is given as 1886 weight percent. The starting materials are monazite and bastnasite.

Recovery

After a complex separation of the other Dysprosiumbegleiter the oxide is reacted with hydrogen fluoride to Dysprosiumfluorid. It is then reduced to metallic dysprosium with calcium to form calcium fluoride. Separation of remaining calcium residues and impurities takes place in an additional remelting in vacuo. After distillation in a high vacuum to reach high purity dysprosium.

Features

Dysprosium is a silver-gray heavy metal that can be bent and stretched. There are two modifications of the rare earth metal: At 1384 ° C, α-dysprosium (hexagonal densest) changes to β-dysprosium (body-centered cubic). The metal is very ignoble and therefore very reactive. In the air it becomes coated with an oxide layer, in water it is slowly attacked with formation of hydroxides, in dilute acids it is dissolved to form salts with formation of hydrogen.

Usage

Economic and technical importance of dysprosium are relatively low. Its output is estimated at less than 100 tonnes per year. It is used in various alloys, in special magnets and with lead alloyed as shielding material in nuclear reactors. However, its use in wind turbine magnets has made these rare earth metals a rare commodity. In addition, the world's largest supplier China is slowing down its delivery in order to increase its own added value.

Other applications:

Dysprosium, together with vanadium and other elements, is used to make laser materials.
Dysprosium is used to dope calcium fluoride and calcium sulfate crystals for dosimeters.
Terbium- and dysprosium-containing alloys show strong magnetostriction and are used in materials testing.
In neodymium-iron-boron magnets, it increases coercivity and extends the usable temperature range.
Dysprosium oxide improves the dielectric behavior of barium titanate for capacitors.
It is occasionally used because of its high capture cross section for thermal neutrons for the production of control rods in nuclear technology.
Dysprosium improves the emission spectrum of high performance halogen lamps.
Dysprosium cadmium chalcogenides serve as an infrared source for the study of chemical reactions.

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