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Europium

Europium is a chemical element with the symbol Eu and atomic number 63. Europium is named after the continent Europe. It is the most reactive of the rare earth elements. It rapidly oxidizes in air. Europium ignites in the air at around 302 degrees Fahrenheit. It is quite pliable (bendable). Although it was first discovered by Paul Émile Lecoq de Boisbaudran in 1890, it is usually credited to French chemist Eugène-Anatole Demarçay, who suspected samples of the discovered samarium were contaminated with an unknown element in 1896, and was able to isolate europium in 1901.

Europium caused a revolution in the 1960s when it was discovered that europium-doped yttrium red phosphor enhanced the picture in the color television industry. There was a mad dash to obtain the limited supply of europium on hand in monazite processors (europium content in monazite was roughly 0.05%). Luckily, europium-rich bastnäsite deposits (0.1% europium content) at Mountain Pass, California contained enough of the element to sustain the industry. Prior to europium, the color-TV red phosphor was very weak, and the other colors had to be muted to maintain color balance.

Europium is not found naturally as a free element. Many minerals are found that contain traces of europium, with the most popular minerals being monazite and bastnäsite. Europium is often included in trace element studies in geochemistry and petrology to help understand the process that form igneous rocks. The europium anomaly is used to help reconstruct the relationships of compounds in igneous rocks. Europium in small amounts happens to be the activator of bright blue fluorescence in samples of fluorite. Fluorite found in Weardale, England was given its name due to the fluorescence, although it was not discovered until much later that europium was determined to be the cause of its brilliance.

Europium has been used in many commercial applications including its use to dope glass to make lasers, and for screening for Down Syndrome and other genetic diseases. It is being studied as a possible use in nuclear reactors. It is used for its red phosphor in color televisions, computer monitors, and fluorescent lamps. Europium is also used in the anti-counterfeiting phosphors in Euro banknotes.

Europium that occurs naturally is composed of 2 isotopes. Europium-151 and europium-153. Europium-153 is the most abundant (52.2% natural abundance). 35 artificial radioisotopes have been characterized, with the most stable being europium-150 with a half-life of 36.9 years. Europium-152 has a half-life of 13.516 years, and europium-154 has a half-life of 8.593 years. All of the remaining isotopes have half-lives of less then 4.8 years and most of those have half-lives of less than 12.2 seconds. Europium has 8 meta states.

The toxicity of europium and its compounds is not fully understood, but there are no indications that it is highly toxic compared to other heavy metals. Europium metal dust presents a fire and explosion hazard. Europium has no known biological role.

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Europium


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