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Jai Ganesh

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Dysprosium

Dysprosium

Gist

Dysprosium (Dy) is a silvery, metallic rare-earth element with atomic number 66. Named for its "hard to obtain" nature, it's found in minerals like xenotime and is used in lasers, nuclear reactor control rods, and magnets due to its unique magnetic and neutron-absorbing properties.

Dysprosium's main use is in alloys for neodymium-based magnets. This is because it is resistant to demagnetisation at high temperatures. This property is important for magnets used in motors or generators. These magnets are used in wind turbines and electrical vehicles, so demand for dysprosium is growing rapidly.

Summary

Dysprosium is a chemical element; it has symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy.

Dysprosium was first identified in 1886 by Paul Émile Lecoq de Boisbaudran, but it was not isolated in pure form until the development of ion-exchange techniques in the 1950s. Dysprosium is used to produce neodymium-iron-boron (NdFeB) magnets, which are crucial for electric vehicle motors and the efficient operation of wind turbines.[9] It is used for its high thermal neutron absorption cross-section in making control rods in nuclear reactors, for its high magnetic susceptibility in data-storage applications, and as a component of Terfenol-D (a magnetostrictive material). Soluble dysprosium salts are mildly toxic, while the insoluble salts are considered non-toxic.

Details

Dysprosium (Dy) is a chemical element, a rare-earth metal of the lanthanide series of the periodic table.

Dysprosium is a relatively hard metal and is silvery white in its pure form. It is quite stable in air, remaining shiny at room temperature. Dysprosium turnings ignite easily and burn white-hot. The metal slowly reacts with water and quickly dissolves in diluted acids—except hydrofluoric acid (HF), in which it forms a protective layer of insoluble DyF3. The metal is a very strong paramagnet above approximately 180 K (−93 °C, or −136 °F); it is antiferromagnetic between about 90 (−183 °C, or −298 °F) and 180 K and ferromagnetic below 90 K.

French chemist Paul-Émile Lecoq de Boisbaudran first found this element (1886) associated with holmium and other heavy lanthanides; French chemist Georges Urbain later (1906) was able to prepare a reasonably pure fraction. Some important mineral sources of dysprosium are laterite ionic clays, xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine. It also occurs in the products of nuclear fission.

The naturally occurring isotopes are all stable and have mass numbers 164 (natural abundance 28.3 percent), 162 (25.5 percent), 163 (24.9 percent), 161 (18.9 percent), 160 (2.33 percent), 158 (0.10 percent), and 156 (0.06 percent). Excluding nuclear isomers, a total of 29 radioactive isotopes of dysprosium are known. They range in mass from 138 to 173. The least stable is dysprosium-139 (half-life 0.6 second), and the most stable is dysprosium-154 (half-life 3.0 × {10}^{6} years).

Commercial separation is performed by liquid-liquid extraction or ion-exchange methods. The metal has been prepared by metallothermic reduction of the anhydrous halides with alkali or alkaline-earth metals. The metal is further purified by vacuum distillation. Dysprosium exists in three allotropic (structural) forms. The α-phase is close-packed hexagonal with a = 3.5915 Å and c = 5.6501 Å at room temperature. When cooled below ~90 K, the ferromagnetic ordering is accompanied by an orthorhombic distortion, β-Dy, of the hexagonal close-packed lattice. The β-phase has a = 3.595 Å, b = 6.184 Å, and c = 5.678 Å at 86 K (−187 °C, or −305 °F). The γ-phase is body-centred cubic with a = 4.03 Å at 1,381 °C (2,518 °F).

The major use of dysprosium is as an alloying addition to Nd2Fe14B permanent magnet materials (in which some of the neodymium is substituted with dysprosium) to increase both the Curie point and especially the coercivity and, therefore, improve the high-temperature performance of the alloy. The metal is also a component of magnetostrictive Terfenol D (Tb0.3Dy0.7Fe2). Dysprosium is used in control rods for nuclear reactors because of its relatively high neutron-absorption cross section; its compounds have been used for making laser materials and phosphor activators, and in metal halide lamps.

Chemically, dysprosium behaves as a typical trivalent rare earth and forms a series of pale yellow compounds in which its oxidation state is +3.

Element Properties

atomic number  :  66
atomic weight  :  162.5
melting point  :  1,412 °C (2,574 °F)
boiling point  :  2,567 °C (4,653 °F)
density  :  8.551 gram/{cm}^{3} (24 °C, or 75 °F)
oxidation state  :  +3.

Additional Information:

Appearance

A bright, silvery metallic element.

Uses

As a pure metal it is little used, because it reacts readily with water and air. Dysprosium’s main use is in alloys for neodymium-based magnets. This is because it is resistant to demagnetisation at high temperatures. This property is important for magnets used in motors or generators. These magnets are used in wind turbines and electrical vehicles, so demand for dysprosium is growing rapidly.

Dysprosium iodide is used in halide discharge lamps. The salt enables the lamps to give out a very intense white light.

A dysprosium oxide-nickel cermet (a composite material of ceramic and metal) is used in nuclear reactor control rods. It readily absorbs neutrons, and does not swell or contract when bombarded with neutrons for long periods.

Biological role

Dysprosium has no known biological role. It has low toxicity.

Natural abundance

In common with many other lanthanides, dysprosium is found in the minerals monazite and bastnaesite. It is also found in smaller quantities in several other minerals such as xenotime and fergusonite.

It can be extracted from these minerals by ion exchange and solvent extraction. It can also be prepared by the reduction of dysprosium trifluoride with calcium metal.

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