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Erbium

physical science Maturity 7-9 Next article →

Erbium is a chemical element with the symbol Er and atomic number 68. It is a member of the lanthanide series, which are also known as rare-earth elements. In its pure form, erbium is a silvery-white, malleable metal that is soft and stable in the air.

ErOPulver
ErOPulver

However, you will never find erbium sitting alone in nature as a pure metal. Instead, it is always found in chemical combinations with other elements. It is a relatively rare substance, found in the Earth's crust at a concentration of about 2.8 mg/kg. Because of its unique physical and optical properties, erbium is essential for modern telecommunications and medical technology.

One of the most important ways erbium works is through its pink-colored Er3+ ions. These ions possess unique optical fluorescent properties that make them perfect for use in lasers. In a process used for fiber optic communications, erbium-doped glasses or crystals act as optical amplification media. To make this work, the Er3+ ions are optically pumped at a wavelength of around 980 nm. This energy causes the ions to radiate light through a process called stimulated emission.

Erbium-glass
Erbium-glass

This mechanism creates a very simple and efficient optical amplifier for signals traveling through fiber optics. This is vital because standard single-mode optical fibers have very minimal loss at the specific wavelength that erbium provides.

Beyond telecommunications, erbium ions are highly useful in the medical field, specifically in dermatology and dentistry. Doctors often use an Er:YAG laser, which relies on the emission of the erbium ion when it is lit at a specific wavelength. This particular wavelength is highly absorbed by water.

Erbium(III)chloride sunlight
Erbium(III)chloride sunlight

Because human tissues, such as skin and teeth, contain a lot of water, the laser energy is deposited very superficially. This shallow deposition makes the laser safe for delicate surgical procedures. In dentistry, the laser can even produce steam. This steam allows for enamel ablation, which is the precise removal of tooth enamel during dental procedures.

The history of erbium is tied to a small village in Sweden called Ytterby. In 1843, the scientist Carl Gustaf Mosander discovered the element while studying a mineral called gadolinite.

Mosander Carl Gustav bw
Mosander Carl Gustav bw

He realized that the sample, which was thought to be pure yttria, actually contained other metal oxides. He named these "erbia" and "terbia" after the Ytterby mine. The early history of these elements was quite confusing for scientists. For a time, the names erbia and terbia were actually switched by mistake due to errors by a spectroscopist named Marc Delafontaine. It was not until 1905 that Georges Urbain and Charles James successfully obtained erbium oxide in its pure form. Pure erbium metal was even harder to produce, and it was not achieved until 1934 by Wilhelm Klemm and Heinrich Bommer.

Erbium has several distinct chemical forms and properties. Its oxide, known as erbia, is a pink compound used as a phosphor activator.

ErOPulver
ErOPulver

Erbium can also form various halides, such as pinkish erbium(III) fluoride or violet erbium(III) chloride. The metal itself is quite electropositive. It reacts slowly with cold water, but it reacts quite quickly with hot water to form erbium hydroxide. Interestingly, erbium displays different magnetic behaviors depending on the temperature. It is ferromagnetic below 19 K, antiferromagnetic between 19 and 80 K, and paramagnetic at temperatures above 80 K.

In nature, erbium is primarily extracted from minerals like monazite, xenotime, and euxenite.

MonaziteUSGOV
MonaziteUSGOV

It can also be found in ion adsorption clays. Historically, separating rare-earth elements from one another was a very difficult and expensive task. However, the development of ion-exchange chromatography in the late 20th century made this much easier and cheaper. Today, southern China has become the principal global supplier of erbium due to its abundant ion adsorption clays. This makes the region a central part of the global supply chain for this essential element.

Erbium also has interesting properties at the atomic level. Scientists have confirmed through transmission electron microscopy that erbium can form propeller-shaped atomic clusters known as Er3N. These clusters have an atomic distance of 0.35 nm and can be isolated by placing them inside fullerene molecules. While erbium does not play a known biological role, some scientists believe it may be able to stimulate metabolism. Additionally, certain isotopes of erbium are useful in medicine. For example, Er-166 can be used in Auger therapy because it decays via electron capture and does not emit gamma radiation. This makes it a specialized tool for studying or treating biological systems.

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🖼️ Images & Media (5)
File:Erbium(III)chloride sunlight.jpg
Erbium(III)chloride sunlight.jpg
File:ErOPulver.jpg
ErOPulver.jpg
File:Mosander Carl Gustav bw.jpg
Mosander Carl Gustav bw.jpg
File:MonaziteUSGOV.jpg
MonaziteUSGOV.jpg
File:Erbium-glass.jpg
Erbium-glass.jpg
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