Erbium
Element 68 · Lanthanide
Erbium is a silvery metal with a slight pink tint in its salts. It is stable in air and nearly always +3 in compounds. Its most valuable property is optical: erbium ions absorb and re-emit light at exactly the wavelengths used in fiber-optic communications.
Erbium-doped fiber amplifiers regenerate weakening light signals without converting them to electricity first — the technology that makes transoceanic internet cables practical. Erbium also colors glass and ceramics pink and dopes YAG lasers used in medicine and dentistry.
Key facts
| Atomic number | 68 |
|---|---|
| Atomic weight | 167.26 |
| Category | Lanthanide |
| Group / Period | — / 6 |
| Block | f |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f12 |
| Common oxidation states | +3 |
| State at STP | Solid |
| Electronegativity | 1.24 |
| Density | 9.07 g/cm³ |
| Melting point | 1529 °C |
| Boiling point | 2868 °C |
Occurrence
Erbium is found in monazite, xenotime, and euxenite, and is separated from the other lanthanides by ion exchange.
Applications
Fiber-optic signal amplifiers (EDFA)
Pink coloring for glass and ceramics
Er:YAG medical and dental lasers
Metallurgy additive
Common compounds
- erbium oxide
- erbium chloride
Without erbium-doped fiber amplifiers, long-distance internet cables would need signal boosters far more often — erbium quietly carries much of the world's data.
Data source: IUPAC standard atomic weights 2021