Lutetium

The element in the form of oxide in 1907 was independently discovered by the French chemist Georges Urbain , the Austrian mineralogist Karl Auer von Welsbach and the American chemist Charles James . All of them discovered lutetium as an impurity to ytterbium oxide, which, in turn, was discovered in 1878 as an admixture to erbium oxide, isolated in 1843 from yttrium oxide , discovered in 1797 in the gadolinite mineral. All of these rare earth elements have very similar chemical properties. The priority of the discovery belongs to J. Urban.

The name of the element, its discoverer, Georges Urbain, came from the Latin name of Paris - Lutetia Parisorum . For ytterbium, from which lutetium was separated, the name neoitterbium was suggested. Von Welsbach, who challenged the discovery priority, proposed the name Cassiopia ( cassiopium ) for lutetium, and aldebaranium for lutetium in honor of the Northern Hemisphere constellation and the brightest star in the Taurus constellation, respectively. Given Urben’s priority in the separation of lutetium and ytterbium, in 1914 the International Atomic Balance Commission adopted the name Lutecium , which in 1949 was changed to Lutetium (the Russian name did not change). However, until the early 1960s, the name Cassiopias were used in the works of German scientists.

To obtain lutetium, it is extracted from minerals along with other heavy rare earth elements. Separation of lutetium from other lanthanides is carried out by extraction , ion exchange, or fractional crystallization, and metallic lutetium is obtained by calcium reduction from LuF ₃ fluoride.

Prices

The price of lutetium metal with a purity of> 99.9% is 3.5–5.5 thousand dollars per 1 kg ^[4] . Lutetium is the most expensive of rare earth metals, due to the difficulty of its separation from a mixture of rare earth elements and limited use.

Physical Properties

Lutetium is a silver-white metal that is easily machined. It is the heaviest element among lanthanides in terms of both atomic weight and density (9.8404 g / cm³). The melting point of lutetium (1663 ° C) is the highest among all rare-earth elements. Due to the effect of lanthanoid compression among all lanthanides, lutetium has the smallest atomic and ionic radii.

Chemical Properties

At room temperature in air, lutetium is covered with a dense oxide film, at a temperature of 400 ° C it is oxidized. When heated, interacts with halogens , sulfur and other non-metals .

Lutetium reacts with inorganic acids to form salts. Upon evaporation of water-soluble salts of lutetium ( chlorides , sulfates , acetates , nitrates ), crystalline hydrates are formed.

In the interaction of aqueous solutions of lutetium salts with hydrofluoric acid , a very poorly soluble precipitate of lutetium fluoride LuF _{3 is formed} . The same compound can be obtained by the reaction of lutetium oxide Lu ₂ O ₃ with gaseous hydrogen fluoride or fluorine .

Lutetium hydroxide is formed by the hydrolysis of its water-soluble salts.

Analytical Definition

Like other rare earth elements , photometrically can be determined with the alizarin red C reagent.

Recording Media

Ferro garnets doped with lutetium (for example, gadolinium-gallium garnet , GGG) are used to produce storage media on CMD ( cylindrical magnetic domains ).

Laser materials

Used to generate laser radiation on lutetium ions. Lutetium scandate, lutetium gallate, lutetium aluminate , doped with holmium and thulium , generate radiation with a wavelength of 2.69 microns , and neodymium ions - 1.06 microns, and are excellent materials for the production of high-power military lasers and for medicine.

Magnetic materials

Alloys for very powerful permanent magnets of the lutetium – iron – aluminum and lutetium – iron – silicon systems have very high magnetic energy, stable properties, and a high Curie point , but the very high cost of lutetium limits their use to only the most critical areas of use (special studies, space and other).

Heat-resistant conductive ceramics

Chromite lutetium finds some use.

Nuclear physics and energy

Lutetium oxide is used in atomic technology, which is small in volume, as a neutron absorber and also as an activation detector . Single crystal lutetium silicate (LSO), doped with cerium , is a very good scintillator and as such is used to detect particles in nuclear physics , elementary particle physics , and nuclear medicine (in particular, in positron emission tomography ).

High-temperature superconductivity

Lutetium oxide is used to control the properties of superconducting metal oxide ceramics.

Metallurgy

Adding lutetium to chromium and its alloys gives the best mechanical properties and improves processability.

In recent years, considerable interest in lutetium is due, for example, to the fact that when doping with lutetium a number of heat-resistant materials and alloys based on chromium-nickel, their service life sharply increases.

Natural lutetium consists of two isotopes : stable ¹⁷⁵ Lu ( isotopic abundance of 97.41%) and long-lived beta-radioactive ¹⁷⁶ Lu (isotope abundance of 2.59%, half-life of 3.78⋅10 ¹⁰ years), which decays into stable hafnium 176 . Radioactive ¹⁷⁶ Lu is used in one of the methods of nuclear geo- and cosmochronology ( lutetium-hafnium dating ). 32 artificial radioisotopes of lutetium (from ¹⁵⁰ Lu to ¹⁸⁴ Lu) are also known, in some of them metastable states (a total of 18) are found.

Content in the earth's crust - 0,00008% by weight. Content in sea water is 0.0000012 mg / l. The main industrial minerals are xenotime , evkenite , bastnezit .

Soluble salts have low toxicity.

• Lutetia at Webelements
• Lutetia in the Popular Library of Chemical Elements
• Lutetium