Europium, Eu, Atomic number 63

General

Europium is a chemical element with the element symbol Eu and atomic number 63. In the periodic table it is in the group of lanthanides and is thus also one of the rare earth metals. Europium is the only addition to americium after a continent named element. Americum, is an artificially produced. radioaktives Transuran der Actinoide, that is irrelevant to our considerations metal.

Paul Emile Lecoq de Boisbaudran entdeckte 1890 in a samarium-gadolinium concentrate unknown spectral lines. The discovery of the element will be awarded to Eugene Anatole Demarcay, the 1896 suspected in the newly discovered element samarium another. 1901 succeeded in the separation of europium.

Metallic europium was produced until years later. Europium occurs only in compounds. In many minerals, it is included; in the spectrum of the sun and some stars, it has been demonstrated. Also important are the minerals monazite and Bastnäsite. Recently, evidence was found, that is a Europiumisotop Alphastraler. As a lower limit for the half-life 1,7 Trillions of years specified.

Extraction

Starting from monazite and bastnaesite, the separation of rare earths by ion exchange, Solvent extraction or electrochemical deposition. In a last step, the high purity europium oxide with lanthanum metal reduced to the metal and sublimation.

Special features

Europium is one of the most reactive rare earth metals. In air, the silvery metal is immediately. At temperatures above 150 ° C, it ignites and burns with a red flame to sesquioxide Eu2O3. In water, it reacts with evolution of hydrogen to hydroxide. With a density of 5,244 g/cm3 is the lightest heavy metal europium, the next lightest titanium (4,507 g/cm3) is already classified as light metals.

While stable 153Eu, were in 2007 Evidence found, that is an alpha emitter 151Eu. As a lower limit for the half-life 1,7 Trillions of years specified. Europium and europium compounds are considered to be toxic. Metal dusts are fire- and potentially dangerous.

Use

  1. Europium(III)-dotiertes Yttriumoxidsulfid Y2O2S:Eu3 forms a red fluorescent (Luminophor) in color picture tubes.
  2. Europium(II)-BaFBr doped barium:Eu2 is the photo-stimulated luminescence (PSL) used
  3. With Eu3 doped solids usually show a red luminescence, Eu 2 can be a function of the host lattice in the whole spectral range (UV bis rot) emit.
  4. Doping in phosphors for light sources such as high-pressure mercury lamps and energy saving lamps.
  5. Dotiermaterial the Szintillationskristallen (as activator).
  6. Organic compounds as shift reagent in NMR spectroscopy.
  7. Europium-tetracycline complexes in fluorescence spectroscopy for the detection of hydrogen peroxide
  8. TRFIA = time-resolved fluoroimmunoassay. Eu3 ions fluoresce in water just short. Therefore, we used chelating, the building to the Eu3 ions around a hydrophobic environment. This leads to a longer duration of the fluorescence. This is distinguishable from all other, shorter-lived fluorescence can, which can occur in organic mixtures.
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