Erbium (Er)
lanthanideSolid
Standard Atomic Weight
167.259 uElectron configuration
[Xe] 6s2 4f12Melting point
1528.85 °CBoiling point
2867.85 °CDensity
9070 kg/m³Oxidation states
0, +1, +2, +3Electronegativity (Pauling)
1.24Ionization energy (1st)
6.1077 eVDiscovery year
1843Atomic radius
175 pmDetails
Erbium is a lanthanide metal and one of the heavier rare-earth elements. In compounds it is dominated by the +3 oxidation state, giving many salts a characteristic pale pink color. Its greatest technological importance comes from optical transitions of Er³⁺ ions, especially in silica glass, where they enable amplification near 1.55 micrometres for fiber-optic communications. It occurs in nature with other rare earths rather than as a native metal.
The pure metal is soft and malleable and has a bright, silvery, metallic luster. As with other rare-earth metals, its properties depend to a certain extent on the impurities present. The metal is fairly stable in air and does not oxidize as rapidly as some of the other rare-earth metals. Naturally occurring erbium is a mixture of six isotopes, all of which are stable. Nine radioactive isotopes of erbium are also recognized. Recent production techniques, using ion-exchange reactions, have resulted in much lower prices of the rare-earth metals and their compounds in recent years. Most of the rare-earth oxides have sharp absorption bands in the visible, ultraviolet, and near infrared. This property, associated with the electronic structure, gives beautiful pastel colors to many of the rare-earth salts.
The name derives from the Swedish town of Ytterby, where the ore gadolinite (in which it was found) was first mined. Erbium was discovered by the Swedish surgeon and chemist Carl-Gustav Mosander in 1843 in a yttrium sample. He separated the yttrium into yttrium, a rose-coloured salt he called terbium and a deep-yellow peroxide that he called erbium.
The mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10), discovered in a quarry near the town of Ytterby, Sweden, has been the source of a great number of rare earth elements. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into three materials, which he named yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia and, by 1877, had reversed their names. What Mosander called erbia is now called terbia and visa versa. From these two substances, Mosander discovered two new elements, terbium and erbium. Today, erbium is primarily obtained through an ion exchange process from the minerals xenotime (YPO4) and euxenite ((Y, Ca, Er, La, Ce, U, Th)(Nb, Ta, Ti)2O6).
Erbium, one of the so-called rare-earth elements on the lanthanide series, is found in the minerals mentioned under dysprosium. In 1842 Mosander separated "yttria" found in the mineral gadolinite, into three fractions which he called yttria, erbia, and terbia. The names erbia and terbia became confused in this early period. After 1860, Mosander's terbia was known as erbia, and after 1877, the earlier known erbia became terbia. The erbia of this period was later shown to consist of five oxides, now known as erbia, scandia, holmia, thulia and ytterbia. By 1905 Urbain and James independently succeeded in isolating fairly pure Er2O3. Klemm and Bommer first produced reasonably pure erbium metal in 1934 by reducing the anhydrous chloride with potassium vapor.
Pure erbium is a silvery-white metal with a metallic lustre. It is soft and malleable compared with many common structural metals, and it slowly tarnishes in air as an oxide layer forms. Finely divided erbium reacts more readily than massive pieces.
Erbium-doped silica glass is used in optical fiber amplifiers and some fiber lasers, where Er³⁺ emits in the low-loss telecommunications window. Erbium-doped crystals and glasses are also used in solid-state lasers, including medical and dental laser systems that couple strongly to water. Small additions of erbium can modify the properties of some alloys and nuclear materials, but these uses are limited compared with optical applications. Erbium oxide is used as a pink colorant in glass and ceramics.
Erbium is alloyed with vanadium to make it softer and easier to shape. Erbium is added to fiber optic cables as a doping agent where it is used as a signal amplifier. Erbium also has some uses in the nuclear power industry.
Erbia, the renamed material that Mosander discovered in 1843, is erbium oxide (Er2O3), one of erbium's compounds. Erbia has a pink color and is used to color glass and glazes. Other erbium compounds include: erbium fluoride (ErF3, erbium chloride (ErCl3 and erbium iodide (ErI3).
Erbium is finding nuclear and metallurgical uses. Added to vanadium, for example, erbium lowers the hardness and improves workability. Erbium oxide gives a pink color and has been used as a colorant in glasses and porcelain enamel glazes.
Isotopes in Biology
Radiolabeled 171Er (with a half-life of 7.5 h) tablets have been used to study bowel movements of individuals using external scintigraphy. Such tablets have an enteric coating and contain small amounts of stable erbium oxide (170Er) initially. The tablets are then irradiated at a low neutron flux to produce radioactively labeled 171Er tablets, via the 170Er (n, γ) 171Er reaction. This method is a noninvasive approach for determining gastric emptying rates and visualizing segments of the digestive system in an individual [479] A. Parr, R. M. Beihn, M. Jay. Int. J. Pharm.32, 251 (1986)., [480] M. C. Theodorakis. Am. Physiol. Soc. Gastrointest. Liver Physiol.239, G39 (1980)..
Isotopes in Medicine
169Er (with a half-life of 9.4 days) is used in radiosynovectomy, which is a regularly practiced radiotherapy, on rheumatoid arthritis patients whose condition is resistant to standard methods of treatment (Fig. IUPAC.68.1). Rheumatoid arthritis is a chronic, inflammatory, autoimmune disease of the joint capsule (synovial sac), which is lined with a thin membrane called the synovium, of an individual’s moveable joints (synovial joints). In radiosynovectomy, the radiopharmaceutical called 169Er- citrate colloid, which contains colloidal particles that are labeled with β-emitting 169Er, is directly injected into the synovial cavity (the cavity between the bones in a moveable joint inside of the synovium) of the affected joint. These radioactive-colloid particles are then phagocytized (engulfed) by macrophage-like synoviocytes as well as other phagocytizing inflammatory cells in the patient’s synovium. Necrosis (tissue death) and the inhabitation of cell proliferation (increase in number of cells) result from the radiation of the synovium and therefore, temporarily halts synovitis (which is the condition of when the synovium thickens with inflammation) and improves synovial joint function [481] F. M. van der Zanta, Z. N. Jahangierb, G. G. M. Gommansa, J. D. Moolenburghc, J. W. G. Jacobs. Appl. Radiat. Isot.65, 649 (2007)., [482] S. J. Kim, K. A. Jung. Clin. Med. Res.5, 244 (2007)., [483] M. E. A. McNeil. The First Year Rheumatoid Arthritis: An Essential Guide for the Newly Diagnosed, Marlowe & Company, New York, NY (2005)., [484] G. Prabhakar, S. S. Sachdev, N. Sivaprasad. Pharma Times41, 11 (2009)..
Erbium chemistry is typical of the trivalent lanthanides. Erbium(III) oxide, Er₂O₃, is a stable pink oxide and an important commercial intermediate. Erbium(III) chloride, ErCl₃, and erbium(III) nitrate, Er(NO₃)₃, form hydrated salts used in preparation and research. Er³⁺ is a hard Lewis acid and forms complexes with oxygen- and nitrogen-donor ligands. The +2 state is uncommon and strongly reducing; the +4 state is not a normal part of erbium chemistry under ordinary conditions.
See more information at the Erbium compound page.
Metallic erbium has low acute toxicity, but dust or turnings can present fire and inhalation hazards, as with many finely divided reactive metals. Soluble erbium salts should be handled as irritants and potential systemic toxicants because rare-earth ions can interact with biological ligands. Erbium has no known essential biological role. Natural erbium is only weakly radioactive in the practical sense; isotope-specific radiation hazards apply mainly to artificially produced radioisotopes.
Erbium is dispersed in the crust in rare-earth minerals such as monazite and xenotime, always mixed with chemically similar lanthanides. Weathering can release Er³⁺ into soils and sediments, where it tends to bind to clays, phosphates, carbonates, and organic matter rather than remain highly mobile. It has no established biological function, and environmental concern is usually linked to mining, separation reagents, and waste streams rather than to erbium alone.
Erbium is obtained as a by-product of rare-earth mining and separation, not from ores mined specifically for erbium. Processing relies on solvent extraction or ion-exchange methods to separate it from neighboring lanthanides with very similar chemistry. Demand is specialized and strongly tied to optical materials, lasers, and colorants, so the market is much smaller than for major light rare earths or magnet materials. Recycling is limited because erbium is often present as a dilute dopant in glass or ceramics, where recovery is technically possible but rarely economical.
Found with other heavier rare earths in xenotime and euxerite.
Erbium is a trace element in the cosmos. Its stable isotopes were made mainly by slow and rapid neutron-capture processes in earlier generations of stars, followed by incorporation into interstellar dust and later planetary material. In meteorites and rocky planets it behaves as a refractory lithophile rare earth and is concentrated with other lanthanides rather than forming separate phases.
- The name erbium comes from Ytterby, the Swedish village that also gave names to yttrium, terbium, and ytterbium.
- Er³⁺ in glass can amplify light directly inside an optical fiber without converting the signal to electricity.
- Erbium oxide is pink, although the pure metal is silvery.
- Natural erbium contains several stable isotopes, with ¹⁶⁶Er the most abundant.
- Erbium and holmium discoveries were historically entangled because rare-earth oxides were difficult to separate.
Images
Properties
Physical
- Atomic radius (empirical)
- 175 pm Compare Atomic radius (empirical) of all elements →
- Covalent radius
- 189 pm Compare Covalent radius of all elements →
- Van der Waals radius
- 235 pm Compare Van der Waals radius of all elements →
- Density
- 9070 kg/m³ Compare Density of all elements →
- Molar volume
- 0.0184 L/mol
- Phase at STP
- Solid Compare Phase at STP of all elements →
- Melting point
- 1528.85 °C Compare Melting point of all elements →
- Boiling point
- 2867.85 °C Compare Boiling point of all elements →
- Specific heat capacity
- 0.168 J/(g·K) Compare Specific heat capacity of all elements →
- Molar heat capacity
- 28.12 J/(mol·K) Compare Molar heat capacity of all elements →
- Crystal structure
- Hexagonal close-packed Compare Crystal structure of all elements →
Chemical
- Electronegativity (Pauling)
- 1.24 Compare Electronegativity (Pauling) of all elements →
- Electron affinity
- 0.312 eV
- Ionization energy (1st)
- 6.1077 eV Compare Ionization energy (1st) of all elements →
- Ionization energy (2nd)
- 11.916041 eV Compare Ionization energy (2nd) of all elements →
- Ionization energy (3rd)
- 22.700078 eV Compare Ionization energy (3rd) of all elements →
- Ionization energy (4th)
- 42.420146 eV Compare Ionization energy (4th) of all elements →
- Ionization energy (5th)
- 65.100224 eV Compare Ionization energy (5th) of all elements →
- Oxidation states
- 0, +1, +2, +3 Compare Oxidation states of all elements →
- Valence electrons
- 3 Compare Valence electrons of all elements →
- Electron configuration
- [Xe] 6s2 4f12
Thermodynamic
- Heat of fusion
- 0.11815308 eV Compare Heat of fusion of all elements →
- Heat of vaporization
- 2.902005 eV Compare Heat of vaporization of all elements →
- Heat of sublimation
- 3.285485 eV
- Heat of atomization
- 3.285485 eV
- Atomization enthalpy
- 3.279266 eV
Nuclear
- Protons
- 68 Compare Protons of all elements →
- Neutrons
- 98 Compare Neutrons of all elements →
- Known isotopes
- 39 Compare Known isotopes of all elements →
- Stable isotopes
- 4 Compare Stable isotopes of all elements →
- Most stable isotope
- Er-166
- Discovery year
- 1843
Abundance
- Abundance (Earth's crust)
- 3.5 mg/kg Compare Abundance (Earth's crust) of all elements →
- Abundance (ocean)
- 8.7 × 10−7 mg/L Compare Abundance (ocean) of all elements →
Crystal Structure
- Lattice constant a
- 356 pm
Electronic Structure
- Electrons per shell
- 2, 8, 18, 30, 8, 2 Compare Electrons per shell of all elements →
Identifiers
- CAS number
- 7440-52-0 Compare CAS number of all elements →
- Term symbol
- 3H6
- InChI
- InChI=1S/Er
- InChI Key
- UYAHIZSMUZPPFV-UHFFFAOYSA-N
Electron Configuration Measured
Er: 4f¹² 6s²[Xe] 4f¹² 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹² 6s²Atomic model
Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.
Schematic atomic model, not to scale.
Atomic Fingerprint
Emission / Absorption Spectrum
Isotope Distribution
| Mass number | Atomic mass (u) | Natural abundance | Half-life |
|---|---|---|---|
| 164 Stable | 163.9292088 ± 0.000002 | 1.6010% | Stable |
| 166 Stable | 165.9302995 ± 0.0000022 | 33.5030% | Stable |
| 167 Stable | 166.9320546 ± 0.0000022 | 22.8690% | Stable |
| 168 Stable | 167.9323767 ± 0.0000022 | 26.9780% | Stable |
Phase / State
Reason: 1503.8 °C below melting point (1528.85 °C)
Schematic, not to scale
Phase transition points
Transition energies
Energy required to melt 1 mol at melting point
Energy required to vaporize 1 mol at boiling point
Energy required to sublime 1 mol at sublimation point
Density
At standard conditions
At standard conditions
Atomic Spectra
Showing 10 of 68. Sorted by ion charge (ascending).
Lines Holdings ?
| Ion | Charge | Total lines | Transition probabilities | Level designations |
|---|---|---|---|---|
| Er I | 0 | 232 | 11 | 13 |
| Er II | +1 | 285 | 11 | 12 |
| Er III | +2 | 120 | 0 | 0 |
Levels Holdings ?
| Ion | Charge | Levels |
|---|---|---|
| Er I | 0 | 674 |
| Er II | +1 | 362 |
| Er III | +2 | 53 |
| Er IV | +3 | 10 |
| Er V | +4 | 2 |
| Er VI | +5 | 2 |
| Er VII | +6 | 2 |
| Er VIII | +7 | 2 |
| Er IX | +8 | 2 |
| Er X | +9 | 2 |
Ionic Radii
| Charge | Coordination | Spin | Radius |
|---|---|---|---|
| +3 | 6 | N/A | 89 pm |
| +3 | 7 | N/A | 94.5 pm |
| +3 | 8 | N/A | 100.4 pm |
| +3 | 9 | N/A | 106.2 pm |
Compounds
Isotopes (4)
| Mass number | Atomic mass (u) | Natural abundance | Half-life | Decay mode | |
|---|---|---|---|---|---|
| 164 Stable | 163.9292088 ± 0.000002 | 1.6010% ± 0.0030% | Stable | stable | |
| 166 Stable | 165.9302995 ± 0.0000022 | 33.5030% ± 0.0360% | Stable | stable | |
| 167 Stable | 166.9320546 ± 0.0000022 | 22.8690% ± 0.0090% | Stable | stable | |
| 168 Stable | 167.9323767 ± 0.0000022 | 26.9780% ± 0.0180% | Stable | stable |
Extended Properties
Covalent Radii (Extended)
- Covalent radius (Pyykkö)
- 165 pm
- Covalent radius (Pyykkö, double)
- 133 pm
Van der Waals Radii
- Alvarez
- 283 pm
- UFF
- 339.1 pm
- MM3
- 267 pm
Atomic & Metallic Radii
- Atomic radius (Rahm)
- 272 pm
Numbering Scales
- Mendeleev
- 35
- Pettifor
- 23
- Glawe
- 22
Electronegativity Scales
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizability & Dispersion
- Dipole polarizability
- 150 a.u.
- Dipole polarizability (unc.)
- 10 a.u.
- C₆ (Gould–Bučko)
- 2150 Ha·Bohr6
Miedema Parameters
- Miedema molar volume
- 18.45 cm3/mol
- Miedema electron density
- 2
Supply Risk & Economics
- Production concentration
- 97
- Relative supply risk
- 10
- Reserve distribution
- 50
- Political stability (top producer)
- 24
- Political stability (top reserve)
- 24
Phase Transitions & Allotropes
| Melting point | 1802.15 K |
| Boiling point | 3141.15 K |
Oxidation State Categories
Advanced Reference Data
Screening Constants (13)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 1.3263 |
| 2 | p | 4.346 |
| 2 | s | 17.7984 |
| 3 | d | 13.6397 |
| 3 | p | 20.3891 |
| 3 | s | 20.9231 |
| 4 | d | 35.7288 |
| 4 | f | 40.0216 |
| 4 | p | 32.8908 |
| 4 | s | 31.768 |
Crystal Radii Detail (4)
| Charge | CN | Spin | rcrystal (pm) | Origin |
|---|---|---|---|---|
| 3 | VI | 103 | from r^3 vs V plots, | |
| 3 | VII | 108.5 | ||
| 3 | VIII | 114.4 | from r^3 vs V plots, | |
| 3 | IX | 120.2 | from r^3 vs V plots, |
Isotope Decay Modes (52)
| Isotope | Mode | Intensity |
|---|---|---|
| 142 | p | — |
| 143 | B+ | — |
| 143 | B+p | — |
| 144 | B+ | — |
| 145 | B+ | 100% |
| 145 | B+p | — |
| 146 | B+ | 100% |
| 146 | B+p | — |
| 147 | B+ | 100% |
| 147 | B+p | — |
X‑ray Scattering Factors (514)
| Energy (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.18333 |
| 10.1617 | — | 0.18626 |
| 10.3261 | — | 0.18925 |
| 10.4931 | — | 0.19229 |
| 10.6628 | — | 0.19537 |
| 10.8353 | — | 0.1985 |
| 11.0106 | — | 0.20168 |
| 11.1886 | — | 0.20739 |
| 11.3696 | — | 0.21399 |
| 11.5535 | — | 0.2208 |
Additional Data
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3.5 milligrams per kilogram
References (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
8.7×10-7 milligrams per liter
References (1)
References
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
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The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
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This section provides all form of data related to element Erbium.
The element property data was retrieved from publications.