Europium (Eu)
lanthanideSolid
Peso atomico standard
151,964 uConfigurazione elettronica
[Xe] 6s2 4f7Punto di fusione
821,85 °CPunto di ebollizione
1528,85 °CDensità
5240 kg/m³Stati di ossidazione
0, +2, +3Elettronegatività (Pauling)
N/DEnergia di ionizzazione (1ª)
5,670385 eVAnno della scoperta
1896Raggio atomico
185 pmDettagli
Europium is a lanthanide rare-earth metal with atomic number 63. It is chemically notable for the relative stability of both Eu³⁺ and Eu²⁺, a contrast to most lanthanides, which are dominated by the +3 state. This redox flexibility controls much of its mineral behavior and its optical technology. Europium is best known for intense, narrow luminescence from Eu³⁺ and Eu²⁺ ions in solid hosts, especially in phosphors and security materials.
As with other rare-earth metals, except for lanthanum, europium ignites in air at about 150 to 180°C. Europium is about as hard as lead and is quite ductile. It is the most reactive of the rare-earth metals, quickly oxidizing in air. It resembles calcium in its reaction with water. Bastnasite and monazite are the principal ores containing europium.
The name derives from the continent of Europe. It was separated from the mineral samaria in magnesium- samarium nitrate by the French chemist Eugène-Anatole Demarçay in 1896. It was also first isolated by Demarçay in 1901.
Europium was discovered by Eugène-Antole Demarçay, a French chemist, in 1896. Demarçay suspected that samples of a recently discovered element, samarium, were contaminated with an unknown element. He was able to produce reasonably pure europium in 1901. Today, europium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements.
Named after Europe. In 1890 Boisbaudran obtained basic fractions from samarium-gadolinium concentrates which had spark spectral lines not accounted for by samarium or gadolinium. These lines subsequently have been shown to belong to europium. The discovery of europium is generally credited to Demarcay, who separated the rare earth in reasonably pure form in 1901. The pure metal was not isolated until recent years.
Pure europium is a soft, silvery metal that tarnishes rapidly in air and can darken as oxide and hydroxide layers form. It is among the more reactive lanthanide metals and is usually stored under inert gas or oil to limit oxidation.
Europium is used chiefly as an activator ion in luminescent materials. Eu³⁺ gives red emission in many oxide and vanadate phosphors, while Eu²⁺ can give blue, green, or other emissions depending on the host lattice. These phosphors have been important in color television tubes, fluorescent lamps, light-emitting diodes, displays, and anti-counterfeiting inks. Europium-doped materials are also used as optical probes in analytical assays, taking advantage of sharp emission lines and long-lived excited states.
Europium is the most reactive of the rare earth elements. There are no commercial applications for europium metal, although it has been used to dope some types of plastics to make lasers. Since it is a good absorber of neutrons, europium is being studied for use in nuclear reactors.
Europium oxide (Eu2O3), one of europium's compounds, is widely used as a red phosphor in television sets and as an activator for yttrium-based phosphors.
Europium-doped plastic has been used as a laser material. With the development of ion-exchange techniques and special processes, the cost of the metal has been greatly reduced in recent years.
Isotopes in Geochronology
For more than 40 years, weapons-grade plutonium was manufactured by the Krasnoyarsk Mining and Chemical Combine in the now closed town of Krasnoyarsk Krai, Russia, using single-pass uranium-graphite production reactors [447] Z. G. Gritchenko, Y. V. Kuznetsov, V. K. Legin, V. N. Strukov. Radiochemistry44, 199 (2002).. Water from the Yenisei River was used for heat removal from the reactor core. Radioactively contaminated water was discharged into the Yenisei River and was a primary source of contamination of bottom sediments and floodland for hundreds of kilometers down gradient from the Krasnoyarsk Mining and Chemical Combine. In 2002, radioactive contamination of the bottom sediments and floodlands was composed primarily of 137Cs, 152Eu, 154Eu, and 60Co [447] Z. G. Gritchenko, Y. V. Kuznetsov, V. K. Legin, V. N. Strukov. Radiochemistry44, 199 (2002).. The decrease in the isotope-amount ratio n(154Eu)/n(152Eu) down the depth profiles (Fig. IUPAC.63.1) enables one to determine the age of bottom sediments and floodlands of the Yenisei River and calculate their average formation rates [447] Z. G. Gritchenko, Y. V. Kuznetsov, V. K. Legin, V. N. Strukov. Radiochemistry44, 199 (2002)..
Isotopes in Industry
Europium isotopes have been used in nuclear-control applications because they are good neutron absorbers [448] C. R. Hammond. “The elements”, in CRC Handbook of Chemistry and Physics, C. Press, Taylor & Francis Group (1998).. 152Eu (with a half-life of 13.5 years), which is produced by 151Eu via the neutron capture reaction 151Eu (n, γ) 152Eu, and 154Eu (with a half-life of 8.59 years) are used as reference sources for calibration in gamma ray spectroscopy (Fig. IUPAC.63.2) [449] K. V. Vimalnatha, M. K. Dasb, M. Ananthakrishnana, N. Ramamoorthy. Appl. Radiat. Isot.62, 17 (2005)..
Isotopes Used as a Source of Radioactive Isotope(s)
Reactions on 153Eu can produce the therapeutic radionuclide 153Sm (with a half-life of about 1.9 days) via fast neutron irradiation 153Eu (n, p) 153Sm [451] M. Al-Abyad, I. Spahn, S. Sudár, M. Morsy, M. N. H. Comsan, J. Csikai, S. M. Qaim, H. H. Coenen. Appl. Radiat. Isot.64, 717 (2006)..
Europium chemistry is dominated by ionic compounds of Eu³⁺, but Eu²⁺ compounds are unusually accessible for a lanthanide and resemble alkaline-earth compounds in size and behavior. Europium(III) oxide, Eu₂O₃, is a common source and phosphor precursor. Europium(II) oxide, EuO, is a ferromagnetic semiconductor studied in solid-state physics. Halides such as europium(III) chloride, EuCl₃, and europium(II) chloride, EuCl₂, illustrate the two main oxidation states. Complexes of Eu³⁺ with organic ligands are widely used for luminescence studies.
See more information at the Europium compound page.
Europium metal presents a fire and chemical hazard because finely divided material can oxidize readily and reacts with moisture and acids to release hydrogen, H₂. Soluble europium salts are not known to have a biological role and should be treated as toxicologically incompletely characterized heavy-metal compounds. Dusts and aerosols are the main practical exposure concern in laboratories and phosphor manufacture. Natural europium is only weakly radioactive through long-lived ¹⁵¹Eu.
Europium occurs dispersed in rare-earth minerals rather than as native metal. It is typically present in monazite, bastnäsite, xenotime, and related deposits, and it follows other trivalent rare earths during weathering and sediment transport. Its ability to exist as Eu²⁺ under reducing geological conditions produces europium anomalies in rocks and minerals, which are useful tracers of magmatic and crustal processes. It has no known essential biological function.
Europium is produced as a separated rare earth from mineral concentrates, not mined as a primary element. Its separation is helped by the distinctive Eu²⁺/Eu³⁺ redox chemistry, but high purity still requires solvent extraction or ion-exchange processing. Demand has historically been tied to red phosphors for lamps and displays; changes in lighting technology and improved phosphor efficiency have reduced some consumption. Recycling from spent fluorescent lamps and display phosphors is technically possible, but collection, contamination, and changing waste streams limit broad recovery. Supply is linked to the wider rare-earth industry and to by-product recovery decisions.
Europium has been identified spectroscopically in the sun and certain stars. Seventeen isotopes are now recognized. Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications.
Europium is a rare element in the universe. Its stable isotopes are made mainly by neutron-capture nucleosynthesis, with the rapid r-process especially important. Because its spectral lines can be measured in old stars, europium is often used by astronomers as a tracer of r-process enrichment. In planetary materials it is lithophile and usually remains in oxide and silicate phases rather than metallic cores.
- Europium is one of the few lanthanides that commonly forms stable divalent compounds.
- Eu²⁺ can substitute for Ca²⁺ or Sr²⁺ in many phosphor host lattices.
- Europium anomalies help identify plagioclase fractionation in igneous rocks.
- The red emission of Eu³⁺ is extremely narrow compared with many organic dyes.
- EuO becomes ferromagnetic at low temperature.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 185 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 198 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 233 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Densità
- 5240 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0289 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 821,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 1528,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Conducibilità termica
- 13,9 W/(m·K) Confronta Conducibilità termica di tutti gli elementi →
- Capacità termica specifica
- 0,182 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 27,66 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Cubica a corpo centrato Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Affinità elettronica
- 0,116 eV
- Energia di ionizzazione (1ª)
- 5,670385 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 11,240039 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 24,840086 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 42,940148 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 63,200218 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- 0, +2, +3 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 3 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Xe] 6s2 4f7
Termodinamiche
- Calore di fusione
- 0,09535161 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 1,824118 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 1,886304 eV
- Calore di atomizzazione
- 1,886304 eV
- Entalpia di atomizzazione
- 1,838628 eV
Nucleari
- Protoni
- 63 Confronta Protoni di tutti gli elementi →
- Neutroni
- 88 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 41 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 0 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Eu-151
- Anno della scoperta
- 1896
Abbondanza
- Abbondanza (crosta terrestre)
- 2 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 1,3 × 10−7 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 461 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 25, 8, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-53-1 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 8S°7/2
- InChI
- InChI=1S/Eu
- Chiave InChI
- OGPBJKLSAFTDLK-UHFFFAOYSA-N
Configurazione elettronica Misurato
Eu: 4f⁷ 6s²[Xe] 4f⁷ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 6s²Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
Nessun isotopo stabile.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 153 Radioattivo | 152,921238 ± 0,0000018 | 52,1900% | 550 Py |
| 134 Radioattivo | 133,9464 ± 0,00032 | N/D | 500 ms |
| 169 Radioattivo | 168,961717 ± 0,000537 | N/D | 420 ms |
| 133 Radioattivo | 132,94929 ± 0,00032 | N/D | 200 ms |
| 168 Radioattivo | 167,957863 ± 0,000429 | N/D | 200 ms |
Fase / Stato
Motivo: 796,9 °C sotto il punto di fusione (821,85 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Spettri atomici
Sono visualizzati 10 di 63. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Eu I | 0 | 350 | 152 | 343 |
| Eu II | +1 | 218 | 13 | 13 |
| Eu III | +2 | 229 | 0 | 0 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Eu I | 0 | 592 |
| Eu II | +1 | 163 |
| Eu III | +2 | 118 |
| Eu IV | +3 | 13 |
| Eu V | +4 | 2 |
| Eu VI | +5 | 2 |
| Eu VII | +6 | 2 |
| Eu VIII | +7 | 2 |
| Eu IX | +8 | 2 |
| Eu X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +2 | 6 | N/D | 117 pm |
| +2 | 7 | N/D | 120 pm |
| +2 | 8 | N/D | 125 pm |
| +2 | 9 | N/D | 130 pm |
| +2 | 10 | N/D | 135 pm |
| +3 | 6 | N/D | 94.69999999999999 pm |
| +3 | 7 | N/D | 101 pm |
| +3 | 8 | N/D | 106.60000000000001 pm |
| +3 | 9 | N/D | 112.00000000000001 pm |
Composti
Isotopi (5)
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 153 Radioattivo | 152,921238 ± 0,0000018 | 52,1900% ± 0,0600% | 550 Py | IS =52.19±0.6% | |
| 134 Radioattivo | 133,9464 ± 0,00032 | N/D | 500 ms | β+ =100%β+p =? | |
| 169 Radioattivo | 168,961717 ± 0,000537 | N/D | 420 ms | β- ? | |
| 133 Radioattivo | 132,94929 ± 0,00032 | N/D | 200 ms | β+ ?β+p ? | |
| 168 Radioattivo | 167,957863 ± 0,000429 | N/D | 200 ms | β- =100%β-n ? |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 168 pm
- Raggio covalente (Pyykkö, legame doppio)
- 134 pm
Raggi di van der Waals
- Alvarez
- 287 pm
- UFF
- 349,3 pm
- MM3
- 294 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 280 pm
Scale di numerazione
- Mendeleev
- 25
- Pettifor
- 18
- Glawe
- 17
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 184 a.u.
- Polarizzabilità dipolare (inc.)
- 20 a.u.
- C₆ (Gould–Bučko)
- 2940 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 19,97 cm3/mol
- Densità elettronica di Miedema
- 2
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 97
- Rischio relativo di approvvigionamento
- 10
- Distribuzione delle riserve
- 50
- Stabilità politica (principale produttore)
- 24
- Stabilità politica (principale detentore di riserve)
- 24
Transizioni di fase e allotropi
| Punto di fusione | 1095,15 K |
| Punto di ebollizione | 1802,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (13)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,2391 |
| 2 | p | 4,282 |
| 2 | s | 16,5292 |
| 3 | d | 13,7472 |
| 3 | p | 19,716 |
| 3 | s | 20,1318 |
| 4 | d | 34,0592 |
| 4 | f | 38,68 |
| 4 | p | 31,1252 |
| 4 | s | 30,132 |
Dettaglio dei raggi cristallini (9)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 2 | VI | 131 | ||
| 2 | VII | 134 | ||
| 2 | VIII | 139 | ||
| 2 | IX | 144 | ||
| 2 | X | 149 | ||
| 3 | VI | 108,7 | from r^3 vs V plots, | |
| 3 | VII | 115 | ||
| 3 | VIII | 120,6 | from r^3 vs V plots, | |
| 3 | IX | 126 | from r^3 vs V plots, |
Modalità di decadimento degli isotopi (63)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 130 | p | 100% |
| 130 | B+ | — |
| 130 | B+p | — |
| 131 | p | 89% |
| 131 | B+ | — |
| 131 | B+p | — |
| 132 | B+ | — |
| 132 | B+p | — |
| 132 | p | 0% |
| 133 | B+ | — |
Fattori di diffusione dei raggi X (514)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,18583 |
| 10,1617 | — | 0,19489 |
| 10,3261 | — | 0,20439 |
| 10,4931 | — | 0,21435 |
| 10,6628 | — | 0,22479 |
| 10,8353 | — | 0,23529 |
| 11,0106 | — | 0,24598 |
| 11,1886 | — | 0,25716 |
| 11,3696 | — | 0,26817 |
| 11,5535 | — | 0,27854 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
2.0 milligrams per kilogram
Riferimenti (1)
- [5] Europium https://education.jlab.org/itselemental/ele063.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.3×10-7 milligrams per liter
Riferimenti (1)
- [5] Europium https://education.jlab.org/itselemental/ele063.html
Sources
Sources of this element.
Europium has been identified spectroscopically in the sun and certain stars. Seventeen isotopes are now recognized. Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications.
Riferimenti (1)
- [6] Europium https://periodic.lanl.gov/63.shtml
Production
Production of this element (from raw materials or other compounds containing the element).
Europium is now prepared by mixing Eu2O3 with a 10%-excess of lanthanum metal and heating the mixture in a tantalum crucible under high vacuum. The element is collected as a silvery-white metallic deposit on the walls of the crucible.
Riferimenti (1)
- [6] Europium https://periodic.lanl.gov/63.shtml
Riferimenti
(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.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
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.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Europium.
The element property data was retrieved from publications.