Europium (Eu)
lanthanideSolid
标准原子量
151.964 u电子排布
[Xe] 6s2 4f7熔点
821.85 °C沸点
1528.85 °C密度
5240 kg/m³氧化态
0, +2, +3电负性（鲍林）
暂无第一电离能
5.670385 eV发现年份
1896原子半径
185 pm详细信息
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.
图片
性质
物理性质
- 原子半径（经验值）
- 185 pm 比较所有元素的原子半径（经验值） →
- 共价半径
- 198 pm 比较所有元素的共价半径 →
- 范德华半径
- 233 pm 比较所有元素的范德华半径 →
- 密度
- 5240 kg/m³ 比较所有元素的密度 →
- 摩尔体积
- 0.0289 L/mol
- 标准温度和压力下的物相
- 固态 比较所有元素的标准温度和压力下的物相 →
- 熔点
- 821.85 °C 比较所有元素的熔点 →
- 沸点
- 1528.85 °C 比较所有元素的沸点 →
- 热导率
- 13.9 W/(m·K) 比较所有元素的热导率 →
- 比热容
- 0.182 J/(g·K) 比较所有元素的比热容 →
- 摩尔热容
- 27.66 J/(mol·K) 比较所有元素的摩尔热容 →
- 晶体结构
- 体心立方 比较所有元素的晶体结构 →
化学性质
- 电子亲和能
- 0.116 eV
- 第一电离能
- 5.670385 eV 比较所有元素的第一电离能 →
- 第二电离能
- 11.240039 eV 比较所有元素的第二电离能 →
- 第三电离能
- 24.840086 eV 比较所有元素的第三电离能 →
- 第四电离能
- 42.940148 eV 比较所有元素的第四电离能 →
- 第五电离能
- 63.200218 eV 比较所有元素的第五电离能 →
- 氧化态
- 0, +2, +3 比较所有元素的氧化态 →
- 价电子
- 3 比较所有元素的价电子 →
- 电子排布
- [Xe] 6s2 4f7
热力学性质
- 熔化热
- 0.09535161 eV 比较所有元素的熔化热 →
- 汽化热
- 1.824118 eV 比较所有元素的汽化热 →
- 升华热
- 1.886304 eV
- 原子化热
- 1.886304 eV
- 原子化焓
- 1.838628 eV
核性质
- 质子
- 63 比较所有元素的质子 →
- 中子
- 88 比较所有元素的中子 →
- 已知同位素
- 41 比较所有元素的已知同位素 →
- 稳定同位素
- 0 比较所有元素的稳定同位素 →
- 最稳定同位素
- Eu-151
- 发现年份
- 1896
丰度
- 丰度（地壳）
- 2 mg/kg 比较所有元素的丰度（地壳） →
- 丰度（海洋）
- 1.3 × 10−7 mg/L 比较所有元素的丰度（海洋） →
晶体结构
- 晶格常数a
- 461 pm
电子结构
- 各电子层电子数
- 2, 8, 18, 25, 8, 2 比较所有元素的各电子层电子数 →
标识符
- CAS登记号
- 7440-53-1 比较所有元素的CAS登记号 →
- 谱项符号
- 8S°7/2
- InChI
- InChI=1S/Eu
- InChI Key
- OGPBJKLSAFTDLK-UHFFFAOYSA-N
电子排布 实测值
Eu: 4f⁷ 6s²[Xe] 4f⁷ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 6s²原子模型
不同同位素的中子数、质量和稳定性不同，但中性原子的电子排布不变。
原子模型示意图，未按比例绘制。
原子指纹
发射 / 吸收光谱
同位素分布
无稳定同位素。
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 |
|---|---|---|---|
| 153 放射性 | 152.921238 ± 0.0000018 | 52.1900% | 550 Py |
| 134 放射性 | 133.9464 ± 0.00032 | 暂无 | 500 ms |
| 169 放射性 | 168.961717 ± 0.000537 | 暂无 | 420 ms |
| 133 放射性 | 132.94929 ± 0.00032 | 暂无 | 200 ms |
| 168 放射性 | 167.957863 ± 0.000429 | 暂无 | 200 ms |
物相 / 状态
原因: 低于熔点（821.85 °C）796.9 °C
示意图，未按比例绘制
相变点
相变能
在熔点熔化1 mol物质所需的能量
在沸点汽化1 mol物质所需的能量
在升华点升华1 mol物质所需的能量
密度
标准条件下
标准条件下
原子光谱
已显示10项，共63项。 按离子电荷升序排列。
收录能级 ?
| 离子 | 电荷 | 能级 |
|---|---|---|
| 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 |
离子半径
| 电荷 | 配位 | 自旋 | 半径 |
|---|---|---|---|
| +2 | 6 | 暂无 | 117 pm |
| +2 | 7 | 暂无 | 120 pm |
| +2 | 8 | 暂无 | 125 pm |
| +2 | 9 | 暂无 | 130 pm |
| +2 | 10 | 暂无 | 135 pm |
| +3 | 6 | 暂无 | 94.69999999999999 pm |
| +3 | 7 | 暂无 | 101 pm |
| +3 | 8 | 暂无 | 106.60000000000001 pm |
| +3 | 9 | 暂无 | 112.00000000000001 pm |
化合物
同位素 (5)
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 | 衰变方式 | |
|---|---|---|---|---|---|
| 153 放射性 | 152.921238 ± 0.0000018 | 52.1900% ± 0.0600% | 550 Py | IS =52.19±0.6% | |
| 134 放射性 | 133.9464 ± 0.00032 | 暂无 | 500 ms | β+ =100%β+p =? | |
| 169 放射性 | 168.961717 ± 0.000537 | 暂无 | 420 ms | β- ? | |
| 133 放射性 | 132.94929 ± 0.00032 | 暂无 | 200 ms | β+ ?β+p ? | |
| 168 放射性 | 167.957863 ± 0.000429 | 暂无 | 200 ms | β- =100%β-n ? |
扩展性质
共价半径（扩展）
- 共价半径（Pyykkö）
- 168 pm
- 共价半径（Pyykkö，双键）
- 134 pm
范德华半径
- Alvarez
- 287 pm
- UFF
- 349.3 pm
- MM3
- 294 pm
原子半径与金属半径
- 原子半径（Rahm）
- 280 pm
编号标度
- Mendeleev
- 25
- Pettifor
- 18
- Glawe
- 17
电负性标度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
极化率与色散
- 偶极极化率
- 184 a.u.
- 偶极极化率（不确定度）
- 20 a.u.
- C₆ (Gould–Bučko)
- 2940 Ha·Bohr6
Miedema参数
- Miedema摩尔体积
- 19.97 cm3/mol
- Miedema电子密度
- 2
供应风险与经济性
- 生产集中度
- 97
- 相对供应风险
- 10
- 储量分布
- 50
- 政治稳定性（最大生产国）
- 24
- 政治稳定性（最大储量国）
- 24
相变与同素异形体
| 熔点 | 1095.15 K |
| 沸点 | 1802.15 K |
氧化态分类
高级参考数据
屏蔽常数 (13)
| n | 轨道 | 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 |
晶体半径详情 (9)
| 电荷 | CN | 自旋 | rcrystal (pm) | 来源 |
|---|---|---|---|---|
| 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, |
同位素衰变方式 (63)
| 同位素 | 模式 | 强度 |
|---|---|---|
| 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+ | — |
X射线散射因子 (514)
| 能量 (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 |
补充数据
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
2.0 milligrams per kilogram
参考文献 (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
参考文献 (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.
参考文献 (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.
参考文献 (1)
- [6] Europium https://periodic.lanl.gov/63.shtml
参考文献
(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.