Erbium

 ERBIUM. Erbium- the chemical element of atomic number 68, a soft, silvery-white metal of the lanthanide. Erbium- is the name for the element with atomic number 68 and is represented by the symbol Er.



INTERESTING FACTS: melting point 1802k (1529°C or 2784°F) boiling point 3141 K (2868°C or 5194°F)

The mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10), discovered in a quarry near the town of Ytterby, Sweden, has been the source of a great number of rare earth elements. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into three materials, which he named yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia and, by 1877, had reversed their names. What Mosander called erbia is now called terbia and visa versa. From these two substances, Mosander discovered two new elements, terbium and erbium. Today, erbium is primarily obtained through an ion exchange process from the minerals xenotime (YPO4) and euxenite ((Y, Ca, Er, La, Ce, U, Th)(Nb, Ta, Ti)2O6).

Erbium (for Ytterby, a village in Sweeden) was discovered by Carl Gustaf Mosander in 1843. Mosander separated "yttria" from the mineral gadolinite into three fractions which he called yttria, erbia, and terbia. He named the new element after the village of Ytterby where large concentrations of yttria and erbium are located. Erbia and terbia, however, were confused at this time. After 1860, terbia was renamed erbia and after 1877 what had been known as erbia was renamed terbia. Fairly pure Er2[|O]3 was independently isolated in 1905 by Georges Urbain and Charles James. Reasonably pure metal wasn't produced until 1934 when Klemm and Bommer reduced the anhydrous chloride with potassium vapor. It was only in the 1990s that the price for Chinese-derived erbium oxide became low enough for erbium to be considered for use as a colorant in art glass.

Erbium is a metallic chemical element grouped among the so-called rare earth metals on the periodic table of elements. Most chemists prefer to refer to these metals at lanthanides, since “rare earth” is a somewhat misleading term. Like other lanthanides, erbium has several applications, especially in the field of nuclear science, and it is also used in the production of some consumer goods. The world's primary source of this element is China, where it is relatively abundant, in marked contrast with the “rare” in “rare earths.”

This element is not usually found isolated in nature, since it is somewhat reactive. Most erbiumis extracted from monzanite or gadolinite, two minerals which contain several metals in the lanthanide group. When erbium is isolated, it is soft, with a silvery luster which can tarnish in moist air. The element is identified with the symbol Er on the periodic table of elements, and it has an atomic number of 68.

Carl Mosander is usually given the credit for the discovery of this element, although he never actually succeeded in isolating it. While the Swedish chemist was performing research on gadolinite from the Ytterby mine in Sweden, he found three distinct fractions in the rock, one of which turned out to be an impure form of erbium. By 1905, chemists had succeeded in isolating erbium, which was named for the Ytterby mine. However, it took another 30 years for chemists to be able to reliably isolate this element.

Erbium is often used as a dopant in lasers, and it can also be used in various metal alloys to make them more workable. The element is also used to dye glass and glazes for porcelain, and it is useful in some nuclear applications. Erbium also produces a distinctive rose colored oxide known as erbia which is used to dye glass, lenses, and cubic zirconium. The pink color can be quite rich, especially under the right lighting.

As is the case with other lanthanides, erbium is presumed to be at least mildly toxic, and most people observe basic safety precautions when handling it. Dust from erbium can pose an explosives hazard, since it will react with the air, and the element has no known biological role in the human body, making ingestion a probably unwise move.

pure erbium metal is soft and malleable and has a bright, silvery, metallic lustre. As with other rare-earth metals, its properties depend to a certain extent on impurities present. The metal is fairly stable in air and does not oxidise as rapidly as some of the other rare-earth metals. erbium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive. For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. <span style="font-family: Arial,Helvetica,sans-serif;">Pure erbium is available through the reduction of ErF3 with calcium metal. <span style="font-family: Arial,Helvetica,sans-serif;">2ErF3 + 3Ca → 2Er + 3CaF2 <span style="font-family: Arial,Helvetica,sans-serif;">This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

<span style="font-family: Arial,Helvetica,sans-serif;">Erbium was discovered in 1843 by the Swedish chemist Carl Gustaf Mosander.

<span style="font-family: Arial,Helvetica,sans-serif;">Four years earlier Mosander had discovered lanthanum. His former supervisor, Jöns Berzelius, had discovered the new element cerium in cerite. Mosander continued to study cerite and was rewarded with the discovery of lanthanum.

<span style="font-family: Arial,Helvetica,sans-serif;">In 1843, Mosander began studying the mineral gadolinite. Gadolinite contained yttria (yttrium oxide) in which Johan Gadolin had discovered the element yttrium in 1794. Mosander wondered if he might repeat his earlier triumph and find another new element hiding with a known element.

<span style="font-family: Arial,Helvetica,sans-serif;">Using ammonium hydroxide he precipitated fractions of different basicity from yttria. In these fractions he found two differently coloured, previously unknown substances. These he called erbia and terbia; they contained the new rare earth metals erbium and terbium. Mosander had now discovered three new elements, all rare earths, and all in minerals other scientists had discarded after making their own discoveries.

<span style="font-family: Arial,Helvetica,sans-serif;">Mosander named erbium and terbium after the Ytterby Mine in Sweden, the source of gadolinite mineral they were discovered in. (The elements yttrium and yttyerbium were also named after the same mine.)

<span style="font-family: Arial,Helvetica,sans-serif;">The identities (and even the existence) of a number of rare earth elements was settled finally by George Urbain in Paris, who carried out tens of thousands of fractional crystallizations of rare earth salts.

<span style="font-family: Arial,Helvetica,sans-serif;">Crystallizations could take years to produce small samples of pure salts.

<span style="font-family: Arial,Helvetica,sans-serif;">Urbain finally put to rest uncertainty about the identities of pure earths whose salts had never before been completely free of other rare earth salts.

<span style="font-family: Arial,Helvetica,sans-serif;">Urbain found there were fifteen rare earth metals – we now recognize seventeen – one of which was erbium. In the process, he discovered the rare earth lutetium, adding his own name to the list of scientists who have discovered elements.

<span style="font-family: Arial,Helvetica,sans-serif;">Metallic erbium was not isolated until 1935 by W. Klemm and H. Bommer who reduced its anhydrous chloride with potassium vapor.