An Overview about the Chemical Element Erbium


Symbol: Er

Atomic Number: 68

Atomic Mass: 167.26 amu (atomic mass units)

Melting Point: 1529C (1802K, 2784F)

Boiling Point: 2868C (3141K, 5194F)

Number of Protons: 68

Number of Electrons: 68

Number of Neutrons: 99

Classification: Rare Earth Metal

Group Name: Lanthanide or Lanthanoid

Crystal Structure: Hexagonal

Density @ 293 K: 8.795 grams per cubic centimeter

Color: silver/white

The history of the discovery of erbium is one of confusion. It starts with the mineral ore gadolinite being found in a quarry near the Swedish village of Ytterby near Vaxholm. In 1843 the Swedish chemist Carl Gustaf Mosander extracted three different materials from this mineral. He named these in honor of the nearby village yttria, erbia and terbia. The chemistry of these three substances was very similar and by 1877 erbia had become known as terbia while terbia was now erbia. Mosander extracted two new rare earth elements from these substances these elements were erbium and terbium. Ytterby has another two elements to which it gives its name: the transition metal yttrium and another rare earth element ytterbium.

Erbium is a soft and malleable metal. Unlike many other rare earth metals erbium is fairly stable in air and does not oxidize easily. The elements ionization energy is 6.108 eV and its oxidation state is +3.

There are six naturally occurring, stable isotopes of erbium. In order of abundance these isotopes are erbium-166 (33.503%), erbium-168 (26.978), erbium-167 (22.869%), erbium-170 (14.91%), erbium-164 (1. 601%) and erbium-162 (0.139%). Erbium has a number of unstable isotopes with mass numbers that range from 144 to 177. The isotope erbium-154m has the shortest half-life at 39 nanoseconds it decays by isomeric transition or alpha decay.

The estimated crustal abundance of the element erbium is 3.5 milligrams per kilogram. It is concentrated in a number of mineral ores. Most of the world’s supply of erbium is extracted from the minerals xenotime and euxenite by the ion exchange process.

Once extracted from its mineral ores erbium has a number of industrial uses.

* It is alloyed to vanadium to make that metal softer and easier to work.

* It has some uses in the nuclear power industry.

* Fiber optic cables are dope with erbium. In this manner it acts as a signal amplifier.

The material now known as erbia (Mosander’s original terbia) is made of erbium oxide (Er2O3). It is pink in color and is used to add color to glass and ceramics.