Dy - Dysprosium

Properties

Dysprosium metal is similar to most of the other rare earth metals, it is a shiny silvery colour and is soft enough to be cut with a knife. It is a member of the lanthanum group of the Periodic Table and is the 42nd most abundant element within the Earth’s crust. Dysprosium is slowly oxidised by oxygen, is rapidly dissolved in acids and reacts with cold water.

History

Dysprosium was discovered in 1886 by the French chemist Paul-Emile Lecoq de Boisbaudran whilst analysing a sample of erbium oxide. Within this sample of erbium oxide, Boisbaudran found two new rare earth oxides: holmium oxide and thulium oxide. Whilst analysing his new oxides he came across yet another new rare earth oxide, that of dysprosium. After exhaustive work on trying to separate this new element, Boisbaudran was successful and in turn called this new element dysprosium, derived from the Greek word dysprositos (hard to get). It was not until 1950 that chemical advances enabled a sample of pure dysprosium to be obtained by Frank Spedding in Iowa.

Sources

Dysprosium is primarily obtained through an ion exchange process from monazite sand.  Dysprosium production is dominated by China, but recently the Japanese chemical group Showa Denko set up a joint venture to extract dysprosium in Vietnam, with the aim of securing a stable, non-Chinese supply of rare earth magnetic materials.

Uses

There are numerous uses for dysprosium, and it is often difficult to find a substitute. Its most common use is in Nd-Fe-B magnets, where the addition of dysprosium prevents the loss of magnetism at high temperatures. Applications include high performance motors, energy-conserving home electronics, and wind power generation.

Its high melting point and thermal neutron absorption cross-section allow dysprosium to be used in nuclear applications. Inside nuclear reactors, dysprosium is used as a cermet, a composite material made of ceramic and sintered metal. Other uses include alloying with special stainless steels, and use in laser materials.