DYSPROSIUM

Dysprosium was discovered in 1886 by the French chemist Paul-Émile Lecoq de Boisbaudran within a sample of holmium oxide (he had previously discovered gallium and samarium in 1875 and 1879 respectively). At that time, holmium oxide was still considered a homogeneous substance. The name of this new element was aptly chosen, as it derives from the Greek word ‘dysprositos’, meaning ‘difficult to obtain’. It was not until around 1950, with the development of ion exchange chromatography by Frank Spedding and colleagues at Iowa State University, that pure dysprosium was first obtained through the invention of ion exchange techniques.

metal ingots

Dysprosium is a dense (specific gravity = 8.540) metal. It is soft, and when cut with aknife, it appears as a silvery metal that oxidizes slowly at room temperatures. The white oxide(Dy2O3) that forms on the outside of the metal sloughs off, exposing a fresh surface of themetal for more oxidation. The oxide of dysprosium is also called dysprosia.

Its melting point is 1,412°C, its boiling point is 2,567°C, and its density is 8.540g/cm³.

There are a total of 39 isotopes of dysprosium, seven of which are stable. Theatomic mass of the stable isotopes ranges from 156 to 164 amu (atomic mass units oratomic weight). The unstable isotopes of dysprosium have half-lives ranging from 150milliseconds to 3.0×10⁺⁶ years. All of the unstable isotopes are radioactive and are producedartificially.

The word dysprosium was derived from the Greek word dysprositos, which means “difficult to approach.”

Dysprosium is the 43rd most abundant element on Earth and ranks ninth in abundanceof the rare-earths found in the Earth’s crust. It is a metallic element that is usually found asan oxide (disprosia). Like most rare-earths, it is found in the minerals monazite and allanite,which are extracted from river sands of India, Africa, South America, and Australia and thebeaches of Florida. It is also found in the mineral bastnasite in California.

Dysprosium was discovered in 1886 by Lecoq de Boisbaudran, but not isolated. Neither the oxide nor the metal was available in relatively pure form until the development of ion-exchange separation and metallographic reduction techniques by Spedding and associates about 1950. Dysprosium occurs along with other so-called rare-earth or lanthanide elements in a variety of minerals such as xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine. The most important sources, however, are from monazite and bastnasite. Dysprosium can be prepared by reduction of the trifluoride with calcium. The element has a metallic, bright silver luster. It is relatively stable in air at room temperature, and is readily attacked and dissolved, with the evolution of hydrogen, by dilute and concentrated mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. Small amounts of impurities can greatly affect its physical properties. While dysprosium has not yet found many applications, its thermal neutron absorption cross-section and high melting point suggest metallurgical uses in nuclear control applications and for alloying with special stainless steels. A dysprosium oxide-nickel cermet has found use in cooling nuclear reactor rods. This cermet absorbs neutrons readily without swelling or contracting under prolonged neutron bombardment. In combination with vanadium and other rare earths, dysprosium has been used in making laser materials. Dysprosium-cadmium chalcogenides, as sources of infrared radiation, have been used for studying chemical reactions. The cost of dysprosium metal has dropped in recent years since the development of ionexchange and solvent extraction techniques, and the discovery of large ore bodies. Thirty-two isotopes and isomers are now known. The metal costs about $6/g (99.9% purity).

Dysprosium, with characteristics similar to most of the other rare-earths, was difficult todiscover. Although dysprosium does not react rapidly with moist air at low temperatures, it does react with water and the halogens at high temperatures. It also reacts in solutions of weakacids. At low temperatures, dysprosium is strongly magnetic.

There are not many uses for dysprosium. Scientists continue to experiment with it as apossible alloy metal (it has a high melting point) to be mixed with steel to make control rodsthat absorb neutrons in nuclear reactors. There are only a few commercial uses for dysprosium,such as a laser material and as a fluorescence activator for the phosphors used to produce thecolors in the older TV and computer cathode ray tubes (CRTs). When combined with steelor nickel as an alloy, it makes strong magnets.

Dysprosium is most commonly used as in Neodymium-iron-boron high strength permanent magnets. While it has one of the highest magnetic moments of any of the rare earths (10.6uB), this has not resulted in an ability to perform on its own as a practical alternative to Neodymium compositions.
It is however now an essential additive in NdFeB production. It is also used in special ceramic compositions based on BaTiO formulations.
Dysprosium is used, in conjunction with Vanadium and other elements, in making laser materials and commercial lighting. Nanofibers of Dysprosium compounds have high strength and large surface area. Therefore, they can be used to reinforce other materials and as a catalyst.
Recent research has examined the use of Dysprosium in Dysprosium-iron-garnet (DyFeG) and silicon implanted with Dysprosium and Holmium to form donor centers.
Dysprosium Metal is an important additive for NdFeB permanent magnets to raise the Curie temperature and improve temperature coefficiency. Another most promising use of high purity Dysprosium Metal is in the magnetostrictive alloy TEFENOL-D. There are also other applications for some special master alloys. Dysprosium Metal can be further processed to various shapes of ingots, pieces, wires, foils, slabs, rods, discs and powder. It is highly susceptible to magnetization, they are employed in various data-storage applications, such as in hard disks.

A soft malleable silvery element of the lanthanoid series of metals. It occurs in association with other lanthanoids. One of its few uses is as a neutron absorber in nuclear reactors; it is also a constituent of certain magnetic alloys.

dysprosium: Symbol Dy. A soft silverymetallic element belonging tothe lanthanoids; a.n. 66; r.a.m.162.50; r.d. 8.551 (20°C); m.p. 1412°C;b.p. 2562°C. It occurs in apatite,gadolinite, and xenotime, fromwhich it is extracted by an ionexchangeprocess. There are sevennatural isotopes and twelve artificialisotopes have been identified. It findslimited use in some alloys as a neutronabsorber, particularly in nucleartechnology. It was discovered by PaulLecoq de Boisbaudran (1838–1912) in1886.

Dysprosium nitrate [Dy₂(NO₃)₃] is a strong oxidizing agent and will ignite when in contactwith organic material. Most dysprosium salts are toxic if ingested or inhaled.

Flammable

reagent type: catalyst
core: dysprosium

Dysprosium is produced primarily from the mining of monazite sands consisting of a mixture of various phosphates and is one of the by-products of the yttrium extraction process. The process of separating dysprosium can use magnetic or buoyancy methods to remove other metallic impurities, followed by ion exchange methods to separate the various rare earth metals.

The resulting dysprosium ions react with fluorine or chlorine to form dysprosium fluoride (DyF3) or dysprosium chloride (DyCl3), respectively, which is then reduced by calcium or lithium metals: 3 Ca + 2 DyF3 → 2 Dy + 3 CaF2 3 Li + DyCl3 → Dy + 3 LiCl The reaction is carried out in a tantalum crucible in a helium atmosphere.

The halides produced during the process and the molten dysprosium will naturally separate due to the difference in specific gravity. After cooling, dysprosium can be separated from other impurities with a knife.