Everything about Erbium totally explained
Erbium is a
chemical element with the symbol
Er and
atomic number 68. A rare, silvery, white metallic
lanthanide; Erbium is a
solid in its normal state. It is a
rare earth element, erbium is associated with several other rare elements in the
mineral gadolinite from
Ytterby in
Sweden.
Notable characteristics
A
trivalent element, pure erbium
metal is malleable (or easily shaped), soft yet stable in air, and doesn't
oxidize as quickly as some other
rare-earth metals. Its
salts are rose-colored, and the element has characteristic sharp
absorption spectra bands in
visible light,
ultraviolet, and near
infrared. Otherwise it looks much like the other rare earths. Its
sesquioxide is called
erbia. Erbium's properties are to a degree dictated by the kind and amount of impurities present. Erbium doesn't play any known biological role, but is thought by some to be able to stimulate
metabolism. Erbium-doped glasses or crystals can be used as optical amplification media, where erbium ions are optically pumped at around 980nm or 1480nm and then radiate light at 1550nm. This process can be used to create
lasers and
optical amplifiers. The 1550nm wavelength is especially important for
optical communications because standard single mode
optical fibers have minimal loss at this particular wavelength.
A large variety of medical applications can be found (for example dermatology, dentistry) by utilizing the 2940nm emission (see ) which is highly absorped in water (about 12000 1/cm).
Applications
Erbium's everyday uses are varied. It is commonly used as a
photographic filter, and because of its resilience it's useful as a metallurgical additive. Other uses:
History
Erbium (for
Ytterby, a town in
Sweden) 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 town 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 Er
2O3 was independently isolated in 1905 by
Georges Urbain and
Charles James. Reasonably pure metal wasn't produced until 1934 when workers reduced the
anhydrous chloride with
potassium vapor.
Occurrence
Like other rare earths, this element is never found as a free element in nature but is found bound in
monazite sand ores. It has historically been very difficult and expensive to separate rare earths from each other in their ores but
ion-exchange production techniques developed in the late 20th century have greatly brought down the cost of production of all rare-earth metals and their
chemical compounds. The principal commercial sources of erbium are from the minerals
xenotime and
euxenite, and most recently, the ion adsorption clays of southern China. In the high-yttrium versions of these ore concentrates, yttrium is about two-thirds of the total by weight, and erbia is about 4-5%. This is enough erbium to impart a distinct pink color to the solution when the concentrate is dissolved in acid. This color behavior is highly similar to what Mosander and the other early workers in the lanthanides would have seen, in their extracts from Ytterby gadolinite.
Isotopes
Naturally occurring erbium is composed of 6 stable
isotopes, Er-162, Er-164, Er-166, Er-167, Er-168, and Er-170 with Er-166 being the most abundant (33.503%
natural abundance). 29
radioisotopes have been characterized, with the most stable being Er-169 with a
half life of 9.4 days, Er-172 with a half-life of 49.3 hours, Er-160 with a half-life of 28.58 hours, Er-165 with a half-life of 10.36 hours, and Er-171 with a half life of 7.516 hours. All of the remaining
radioactive isotopes have half-lifes that are less than 3.5 hours, and the majority of these have half lifes that are less than 4 minutes. This element also has 13
meta states, with the most stable being Er-167m (t
½ 2.269 seconds).
The isotopes of erbium range in
atomic weight from 142.9663
u (Er-143) to 176.9541 u (Er-177). The primary
decay mode before the most abundant stable isotope, Er-166, is
electron capture, and the primary mode after is
beta decay. The primary
decay products before Er-166 are element 67 (
holmium) isotopes, and the primary products after are element 69 (
thulium) isotopes.
Precautions
As with the other lanthanides, erbium compounds are of low to moderate
toxicity, although their toxicity hasn't been investigated in detail. Metallic erbium in dust form presents a fire and explosion hazard.
Further Information
Get more info on 'Erbium'.
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