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For color TV tubes. | Atomic Number: | 63 | Atomic Symbol: | Eu | | Atomic Weight: | 151.96 | Electron Configuration: | 2-8-25-8-2 | | Shells: | 2,8,18,25,8,2 | Filling Orbital: | 4f7 | | Melting Point: | 822oC | Boiling Point: | 1597oC | | Description: | Soft Silver rare earth metal. | | Uses: | Used with yttrium oxide to make red phosphors for color
televisions. |
History(Europe) In 1890 Boisbaudran obtained basic fractions from
samarium-gadolinium concentrates which had spark spectral lines not accounted
for by samarium or gadolinium. These lines subsequently have been shown to
belong to europium. The discovery of europium is generally credited to Demarcay,
who separated the rare earth in reasonably pure form in 1901. The pure metal was
not isolated until recent years.
Properties- Europium is now prepared by mixing Eu2O3 with a 10%-excess of lanthanum
metal and heating the mixture in a tantalum crucible under high vacuum.
- The element is collected as a silvery-white metallic deposit on the walls of
the crucible.
- As with other rare-earth metals, except for lanthanum, europium ignites in
air at about 150 to 180C.
- Europium is about as hard as lead and is quite ductile.
- It is the most reactive of the rare-earth metals, quickly oxidizing in air.
- It resembles calcium in its reaction with water.
- Bastnasite and monazite are the principal ores containing europium.
- Europium has been identified spectroscopically in the sun and certain stars.
IsotopesSeventeen isotopes are now recognized. Europium isotopes are
good neutron absorbers and are being studied for use in nuclear control
applications.
Uses- Europium oxide is now widely used as a phospor activator and
europium-activated yttrium vanadate is in commercial use as the red phosphor in
color TV tubes.
- Europium-doped plastic has been used as a laser material.
- With the development of ion-exchange techniques and special processes, the
cost of the metal has been greatly reduced in recent years.
CostsEuropium is one of the rarest and most costly of the rare-earth
metals. It is priced about about $7500/kg.
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