Yttrium, And, Atomic number 39

General

Yttrium [ʏtriʊm] is a chemical element with the element symbol Y and atomic number 39. It is one of the rare earth and transition metals, in the periodic table it is in the 5. Period and the 3. Subgroup (group 3) or scandium. Yttrium is named after the first discovery, the pit Ytterby near Stockholm, named, as well as ytterbium, Terbium and erbium.
Yttrium (von Ytterby, Pit near the Swedish capital of Stockholm) was 1794 Johan Gadolin Ytterbit discovered in the mineral. 1824 Friedrich Wöhler made her impure yttrium by reducing yttrium chloride with potassium. Only 1842 succeeded Carl Gustav Mosander the separation of yttrium from the accompanying elements erbium and terbium.
Yttrium is found in nature not present in the elemental state. Yttrium minerals (Yttererden) are always twinned with other rare-earth. Also in uranium ores, it may be included. Commercially exploitable zircon are up to 3 % With yttrium and bastnaesite 0,2 % Yttrium. Furthermore, it is the main component of the xenotime (And[PO4]).
Large Monazitvorkommen, the beginning of the 19. Century in Brazil and India were discovered and exploited, these two countries made a major producer of Yttriumerzen. It was not until the opening of the Mountain Pass mine in California, which until the 1990s promoted large amounts of bastnaesite, made the U.S. the main producers of yttrium, although there is little degraded bastnaesite contains yttrium. Since the closure of these mines is China 60 % the largest producer of Rare earth. These are used in a mine near Bayan Kuang, the ore contains xenotime, of clay minerals and ion absorbing, are mined mainly in South China, won.

Extraction

The separation of the rare earths from one another is an expensive step in the production of yttrium. Fractional crystallization of salt solutions was initially the preferred method, This was used early on for the separation of rare earths in the laboratory. Was not until the introduction of ion chromatography, it is possible, to separate the rare earths on an industrial scale.
The concentrated yttrium oxide is converted to the fluoride. The subsequent reduction to the metal takes place in a vacuum induction furnace with calcium.

Special features

Yttrium is fairly stable in air, but darkens to light. At temperatures above 400 ° C may ignite fresh interfaces. Finely divided yttrium is relatively unstable. Yttrium has a low neutron capture cross.
In its compounds it is usually trivalent. However, there are cluster compounds, where yttrium oxidation < 3 can assume.
A total of 32 Isotopes between 76Y and 108y, and other 24 Kernisomere known. Of these, only one of 89Y, from the well is only natural yttrium, stable. It is thus at yttrium to one of 22 Pure elements. The most stable radioisotopes are 88Y with a half-life of 106,65 Days and 91Y with a half-life of 58,51 Meet. All other isotopes have a half-life less than a day, except for 87Y, which has a half-life of 79,8 Half hours and with 90Y 64 Hours. Yttrium isotopes are among the most common products of the fission of uranium in nuclear reactors and nuclear explosions.

Use

Metallic Yttrium is used in nuclear reactor technology for pipes. An yttrium-cobalt alloy can be used as a permanent magnet. Yttrium is used as material for the heat in the ion sources of mass spectrometers used. In metallurgy are used for grain refining low Yttriumzusätze, For example, in iron-chromium-aluminum heating element alloys, Chrome, Molybdenum, Titan- and zirconium alloys. In Aluminium- and magnesium alloys, it has strength-increasing. Technically important are the yttrium oxide:
Yttrium nitrate as a coating material in a mantle
Yttrium-aluminum-shell (YAG) serves as a laser crystal
Yttrium-Eisengranat (YIG) as a microwave filter
Yttrium stabilized zirconia as solid electrolyte in fuel cells (SOFC, Solid Oxide Fuel Cell)
The most important use of yttrium and Yttriumoxidsulfide However, the versatility in with trivalent europium (red) und Thulium (blue) dotierten Luminophoren (Phosphors) in television picture tubes, Fluorescent tubes and radar.
Furthermore, yttrium ceramics and alloys used in:
Lambda-Sonden
Superconductors (of. B. Yttrium-Barium-Kupferoxid YBa2Cu3O7-x)
ODS alloys
Spark
As a pure beta emitter 90Y is in nuclear medicine used to treat, For example, for radiation synovectomy.
Yttrium is considered to be non-essential and toxic (MAK-Wert = 5 mg/m3).

General
Name, Symbol

Atomic number

Yttrium, And, 39
Series Transition metals
group, Period, Block 3, 5, d
Appearance silvery white
CAS-Nummer 7440-65-5
Mass fraction of element 26 ppm
Atomic
Atomic mass 88,90585 you
Atomradius 180 pm
Kovalenter Radius 190 pm
Elektronenkonf. [Kr] 4d(1) 5s2
1. Ionization 600 KJ / mol
2. Ionization 1180 KJ / mol
3. Ionization 1980 KJ / mol
Physically
Physical State fixed
Crystal structure hexagonal
Density 4,472 g/cm3
Magnetism paramagnetisch (χm = 1,2 * 10(-4))
Melting point 1799 K (1526 C)
Boiling point 3609 K (3336 C)
Molar Volume 19,88 * 10(-6)m(3)/mol
Heat of vaporization 380 KJ / mol
Schmelzwärme 11,4 KJ / mol
Electrical conductivity 1,66*10(6) A/(V * m)
Thermal conductivity 17 W /(m*K)
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