← Periodic table · Lanthanides
Erbium (Er)
Erbium (symbol Er) is the chemical element with atomic number 68: a lanthanide (rare earth), solid at 0 °C, with an atomic mass of 167.26 u. Discovered in 1843 (Carl Gustaf Mosander).
Erbium has a precious talent: when excited by a laser, it amplifies light at 1,550 nm, precisely the wavelength that travels best through optical fiber. Erbium-doped fiber amplifiers, invented in 1987, made intercontinental undersea cables possible. It also tints glass and jewelry pink.
Key facts
- Atomic number
- 68
- Symbol
- Er
- French name
- Erbium
- Atomic mass
- 167.26 u
- Molar mass
- 167.26 g/mol
- Family
- Lanthanides
- Position
- period 6, f-block
- State at 0 °C
- Solid
- Melting point
- 1,528.9 °C
- Boiling point
- 2,867.9 °C
- Density
- 9.07 g/cm³
- Electronegativity (Pauling)
- 1.24
- First ionization energy
- 589 kJ/mol
- Atomic radius
- 175 pm
- Electron configuration
- [Xe] 4f¹² 6s²
- Abundance in Earth's crust
- 3.5 ppm (44th most abundant element)
- Indicative price
- 26 $/kg (order of magnitude)
- Radioactive
- no
- Discovery
- 1843, Carl Gustaf Mosander
Origin of the name
From Ytterby, a Swedish village.
What does erbium look like?
A soft, malleable, silvery-gray metal, fairly stable in air. Its oxide is a pink powder.
Where is erbium found?
About 3.5 ppm of Earth's crust, more than tin. It is found in xenotime, euxenite and ionic clays.
Natural sources
- Xenotime
- Euxenite
- Gadolinite
- Ion-adsorption clays
How is erbium produced?
Separated by ion exchange or solvent extraction. Only tiny amounts are needed to dope optical fiber: a few hundred parts per million is enough.
Top producers
- China
- Myanmar
What is erbium used for?
- Optical amplifiers in long-distance telecom cables.
- Erbium-YAG lasers in dermatology and dentistry.
- Pink coloring for glass, enamels and cubic zirconia.
- Vanadium alloys that are easier to work.
In everyday life
- A transatlantic Internet connection
- Pink-tinted sunglass lenses
- Laser skin treatment at a clinic
Role in living things
No known biological role; low toxicity.
Hazards of erbium
Low toxicity; flammable dust. Erbium lasers are dangerous to the eyes.
Cosmic origin
- Neutron stars: Created when two neutron stars collide — the “forge” of gold.
History of erbium
Mosander identified it in 1843 in yttria from Ytterby, Sweden. Relatively pure metal wasn't obtained until 1934.
Did you know?
- Almost all intercontinental Internet traffic is amplified by erbium atoms at the bottom of the oceans.
- Its laser emits at 2.94 micrometers, the wavelength best absorbed by water: it vaporizes surface tissue with great precision.
- Ytterby gave its name to four elements, erbium among them.
Isotopes of erbium
Erbium has six stable isotopes, erbium-166 being the most abundant.
- erbium-162: 0.139% of natural erbium, stable
- erbium-164: 1.601% of natural erbium, stable
- erbium-166: 33.503% of natural erbium, stable
- erbium-167: 22.869% of natural erbium, stable
- erbium-168: 26.978% of natural erbium, stable
- erbium-169: radioactive, half-life 9.39 days. Injected into small joints to treat inflammatory arthritis.
- erbium-170: 14.91% of natural erbium, stable
Related elements
Same family (lanthanides): Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu).