Gadolinium (Gd)
lanthanideSolid
标准原子量
157.25 u电子排布
[Xe] 6s2 4f7 5d1熔点
1312.85 °C沸点
3272.85 °C密度
7900 kg/m³氧化态
0, +1, +2, +3电负性（鲍林）
1.2第一电离能
6.1498 eV发现年份
1886原子半径
180 pm详细信息
Gadolinium is a silvery lanthanide metal and one of the middle rare-earth elements. Its chemistry is dominated by the +3 oxidation state, but its seven unpaired 4f electrons give it unusually strong magnetic behavior for a rare-earth element. Natural gadolinium is a mixture of stable isotopes, with ¹⁵²Gd very long-lived and weakly radioactive. The element is technologically important in magnetic materials, neutron absorption, phosphors, and medical contrast agents.
As with other related rare-earth metals, gadolinium is silvery white, has a metallic luster, and is malleable and ductile. At room temperature, gadolinium crystallizes in the hexagonal, close-packed alpha form. Upon heating to 1235°C, alpha gadolinium transforms into the beta form, which has a body-centered cubic structure.
The metal is relatively stable in dry air, but tarnishes in moist air and forms a loosely adhering oxide film which falls off and exposes more surface to oxidation. The metal reacts slowly with water and is soluble in dilute acid.
Gadolinium has the highest thermal neutron capture cross-section of any known element (49,000 barns).
The name derives from the mineral gadolinite, in which it was found, and that had been named for the Finnish rare earth chemist Johan Gadolin. Gadolinium was discovered by the Swiss chemist Jean-Charles Galissard de Marignac in 1886, who produced a white oxide in a samarskite mineral. In 1886, the French chemist Paul-Emile Lecoq de Boisbaudran gave the name gadolinium.
Spectroscopic evidence for the existence of gadolinium was first observed by the Swiss chemist Jean Charles Galissard de Marignac in the minerals didymia and gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10) in 1880. Today, gadolinium is primarily obtained from the minerals monazite ((Ce, La, Th, Nd, Y)PO4) and bastnasite ((Ce,La,Y)CO3F).
From gadolinite, a mineral named for Gadolin, a Finnish chemist. The rare earth metal is obtained from the mineral gadolinite. Gadolinia, the oxide of gadolinium, was separated by Marignac in 1880 and Lecoq de Boisbaudran independently isolated it from Mosander's yttria in 1886.
Pure gadolinium is a soft, bright, silvery-white metal when freshly cut. It tarnishes in air and can form a darker oxide surface. At ordinary pressure it is ferromagnetic below about 20 °C, close enough to room temperature that modest temperature changes strongly affect its magnetism.
Gadolinium is used where high magnetic moment or high neutron-capture ability is valuable. Gadolinium compounds are used in some magnetic resonance imaging contrast agents, where chelation is essential to control toxicity. Gadolinium oxide is used in phosphors and scintillators, and gadolinium gallium garnet has served as a substrate and optical material. Gadolinium is also used in control materials and burnable neutron absorbers in some nuclear reactors, often as gadolinium oxide mixed into fuel.
Gadolinium has the greatest ability to capture thermal neutrons of all known elements and can be used as control rods for nuclear reactors. Unfortunately, the two isotopes best suited for neutron capture, gadolinium-155 and gadolinium-157, are present in gadolinium in small amounts. As a result, gadolinium control rods quickly lose their effectiveness.
Gadolinium can be combined with yttrium to form garnets that have applications in microwave technology. Gadolinium can be alloyed with iron, chromium and other metals to improve their workability and their resistance to high temperatures and oxidation. Gadolinium compounds are used to make phosphors for color televisions.
Gadolinium yttrium garnets are used in microwave applications and gadolinium compounds are used as phosphors in color television sets.
The metal has unusual superconductive properties. As little as 1 percent gadolinium improves the workability and resistance of iron, chromium, and related alloys to high temperatures and oxidation.
Gadolinium ethyl sulfate has extremely low noise characteristics and may find use in duplicating the performance of amplifiers, such as the maser.
The metal is ferromagnetic. Gadolinium is unique for its high magnetic movement and for its special Curie temperature (above which ferromagnetism vanishes) lying just at room temperature, meaning it could be used as a magnetic component that can sense hot and cold.
Isotopes in Earth/Planetary Science
The lunar surface is continuously exposed to cosmic radiation, and the interaction between planetary material and cosmic rays produces secondary neutrons. The neutron flux can be investigated using the large neutron capture cross sections of 149Sm, 155Gd, and 157Gd. For example, 157Gd will absorb neutrons and be converted to 158Gd. On a cross plot of n(158Gd)/n(160Gd) isotope-amount ratio and n(157Gd)/n(160Gd) isotope-amount ratio (Fig. IUPAC.64.1), values will move from the lower right corner to the upper left corner of the cross plot with increasing time or increasing flux.
Isotopes in Medicine
The addition of 157Gd to Neutron Capture Therapy (NCT) has been shown to be more effective at targeting tumors than the previous method of using only 10B for the treatment (Fig. IUPAC.64.2) [453] C. N. Culbertson, T. Jevremovic. Phys. Med. Biol.48, 3943 (2003).. 153Gd (with a half-life of 0.66 years) is used in the production of photon line sources (an optical source that emits one or more spectrally narrow lines as opposed to a continuous spectrum) to manufacture 153Gd line sources [454] V. M. Lebedev, J. N. Gordeev, E. A. Karelin, V. D. Gavrilov. Appl. Radiat. Isot.53, 829 (2000).. 153Gd is also used as a photon source of the dual-photon absorptiometry (DPA) technique that is used to measure bone mineral content (BMC). Studies for this technique have been conducted in horses and humans [455] A. Moure, P. Reichmann, H. R. Gamba. Phys. Med. Biol.48, 3851 (2003)., [456] P. Tothill, M. A. Smith, D. Sutton. Br. J. Radiol.56, 829 (1983)..
Gadolinium chemistry is mainly that of Gd³⁺ salts and oxides. Gadolinium(III) oxide, Gd₂O₃, is a stable refractory oxide and a common starting material. Gadolinium(III) chloride, GdCl₃, and gadolinium(III) nitrate, Gd(NO₃)₃, form hydrated salts and coordination complexes. Gadolinium(III) sulfate, Gd₂(SO₄)₃, and many organic chelates are also important. The +2 state is known in specialized solid-state and organometallic chemistry, but it is not the normal aqueous form.
See more information at the Gadolinium compound page.
Metallic gadolinium dust can burn and should be treated as a reactive metal powder. Soluble gadolinium salts are toxic at sufficient dose, largely because free Gd³⁺ can interfere with calcium-dependent biological processes. Medical contrast agents use tightly bound complexes, but release or retention of gadolinium is a recognized safety concern, especially in vulnerable patients. Stable gadolinium isotopes do not present a radiological hazard of practical importance.
Gadolinium occurs in nature dispersed with other rare-earth elements in minerals such as monazite and bastnäsite. It is not known to have an essential biological role. In soils and waters it tends to bind strongly to minerals, phosphates, carbonates, and organic matter rather than remain as a simple free ion. Anthropogenic gadolinium from contrast agents can pass through wastewater systems and has been detected as anomalous rare-earth patterns in some surface waters.
Gadolinium is not mined as a primary metal. It is recovered during processing of rare-earth ores, with separation from chemically similar lanthanides by solvent extraction or ion-exchange methods. Supply depends on the rare-earth industry as a whole and on the economics of separating mixed concentrates into individual oxides. Demand is smaller than for neodymium or cerium but important in medical imaging, nuclear technology, phosphors, and specialty magnetic materials. Recycling is limited and is most practical from concentrated industrial scrap rather than diffuse medical releases.
Gadolinium is found in several other minerals, including monazite and bastnasite, both of which are commercially important. With the development of ion-exchange and solvent extraction techniques, the availability and prices of gadolinium and the other rare-earth metals have greatly improved. The metal can be prepared by the reduction of the anhydrous fluoride with metallic calcium.
Gadolinium is a heavy element made mainly by neutron-capture processes in earlier generations of stars. Its stable isotopes include products associated with both slow and rapid neutron capture. In the Solar System it is far less abundant than iron or the light elements, but it follows the general rare-earth pattern in meteorites and planetary materials.
- Natural gadolinium has one of the highest thermal-neutron absorption capacities among stable-element mixtures.
- The element is named through gadolinite, a mineral ultimately named for Johan Gadolin.
- Gadolinium becomes ferromagnetic only just below ordinary room temperature.
- Free Gd³⁺ is far more hazardous than gadolinium held in approved chelating ligands.
- Gadolinium anomalies in rivers can trace releases from medical imaging agents.
图片
性质
物理性质
- 原子半径（经验值）
- 180 pm 比较所有元素的原子半径（经验值） →
- 共价半径
- 196 pm 比较所有元素的共价半径 →
- 范德华半径
- 237 pm 比较所有元素的范德华半径 →
- 密度
- 7900 kg/m³ 比较所有元素的密度 →
- 摩尔体积
- 0.0199 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
- 1312.85 °C 比较所有元素的熔点 →
- 沸点
- 3272.85 °C 比较所有元素的沸点 →
- 比热容
- 0.236 J/(g·K) 比较所有元素的比热容 →
- 摩尔热容
- 37.03 J/(mol·K) 比较所有元素的摩尔热容 →
- 晶体结构
- 六方密堆积 比较所有元素的晶体结构 →
化学性质
- 电负性（鲍林）
- 1.2 比较所有元素的电负性（鲍林） →
- 电子亲和能
- 0.132 eV
- 第一电离能
- 6.1498 eV 比较所有元素的第一电离能 →
- 第二电离能
- 12.076042 eV 比较所有元素的第二电离能 →
- 第三电离能
- 20.540071 eV 比较所有元素的第三电离能 →
- 第四电离能
- 44.440153 eV 比较所有元素的第四电离能 →
- 第五电离能
- 64.800223 eV 比较所有元素的第五电离能 →
- 氧化态
- 0, +1, +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 5d1
热力学性质
- 熔化热
- 0.10364305 eV 比较所有元素的熔化热 →
- 汽化热
- 3.109292 eV 比较所有元素的汽化热 →
- 升华热
- 4.124994 eV
- 原子化热
- 4.124994 eV
- 原子化焓
- 4.119811 eV
核性质
- 质子
- 64 比较所有元素的质子 →
- 中子
- 94 比较所有元素的中子 →
- 已知同位素
- 40 比较所有元素的已知同位素 →
- 稳定同位素
- 5 比较所有元素的稳定同位素 →
- 最稳定同位素
- Gd-158
- 发现年份
- 1886
丰度
- 丰度（地壳）
- 6.2 mg/kg 比较所有元素的丰度（地壳） →
- 丰度（海洋）
- 7 × 10−7 mg/L 比较所有元素的丰度（海洋） →
晶体结构
- 晶格常数a
- 364 pm
电子结构
- 各电子层电子数
- 2, 8, 18, 25, 9, 2 比较所有元素的各电子层电子数 →
标识符
- CAS登记号
- 7440-54-2 比较所有元素的CAS登记号 →
- 谱项符号
- 9D°2
- InChI
- InChI=1S/Gd
- InChI Key
- UIWYJDYFSGRHKR-UHFFFAOYSA-N
电子排布 实测值
Gd: 4f⁷ 5d¹ 6s²[Xe] 4f⁷ 5d¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 5d¹ 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
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 |
|---|---|---|---|
| 154 稳定 | 153.9208741 ± 0.0000017 | 2.1800% | 稳定 |
| 155 稳定 | 154.9226305 ± 0.0000017 | 14.8000% | 稳定 |
| 156 稳定 | 155.9221312 ± 0.0000017 | 20.4700% | 稳定 |
| 157 稳定 | 156.9239686 ± 0.0000017 | 15.6500% | 稳定 |
| 158 稳定 | 157.9241123 ± 0.0000017 | 24.8400% | 稳定 |
物相 / 状态
原因: 低于熔点（1312.85 °C）1287.8 °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64项。 按离子电荷升序排列。
收录能级 ?
| 离子 | 电荷 | 能级 |
|---|---|---|
| Gd I | 0 | 634 |
| Gd II | +1 | 321 |
| Gd III | +2 | 28 |
| Gd IV | +3 | 5 |
| Gd V | +4 | 2 |
| Gd VI | +5 | 2 |
| Gd VII | +6 | 2 |
| Gd VIII | +7 | 2 |
| Gd IX | +8 | 2 |
| Gd X | +9 | 2 |
离子半径
| 电荷 | 配位 | 自旋 | 半径 |
|---|---|---|---|
| +3 | 6 | 暂无 | 93.8 pm |
| +3 | 7 | 暂无 | 100 pm |
| +3 | 8 | 暂无 | 105.3 pm |
| +3 | 9 | 暂无 | 110.7 pm |
化合物
同位素 (5)
Natural gadolinium is a mixture of seven isotopes, but 17 isotopes of gadolinium are now recognized. Although two of these, 155Gd and 157Gd, have excellent capture characteristics, they are only present naturally in low concentrations. As a result, gadolinium has a very fast burnout rate and has limited use as a nuclear control rod material.
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 | 衰变方式 | |
|---|---|---|---|---|---|
| 154 稳定 | 153.9208741 ± 0.0000017 | 2.1800% ± 0.0300% | 稳定 | stable | |
| 155 稳定 | 154.9226305 ± 0.0000017 | 14.8000% ± 0.1200% | 稳定 | stable | |
| 156 稳定 | 155.9221312 ± 0.0000017 | 20.4700% ± 0.0900% | 稳定 | stable | |
| 157 稳定 | 156.9239686 ± 0.0000017 | 15.6500% ± 0.0200% | 稳定 | stable | |
| 158 稳定 | 157.9241123 ± 0.0000017 | 24.8400% ± 0.0700% | 稳定 | stable |
扩展性质
共价半径（扩展）
- 共价半径（Pyykkö）
- 169 pm
- 共价半径（Pyykkö，双键）
- 135 pm
- 共价半径（Pyykkö，三键）
- 132 pm
范德华半径
- Alvarez
- 283 pm
- UFF
- 336.8 pm
- MM3
- 271 pm
原子半径与金属半径
- 原子半径（Rahm）
- 277 pm
编号标度
- Mendeleev
- 27
- Pettifor
- 27
- Glawe
- 26
电负性标度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 7
- Robles–Bartolotti
- 6
极化率与色散
- 偶极极化率
- 158 a.u.
- 偶极极化率（不确定度）
- 20 a.u.
- C₆ (Gould–Bučko)
- 2340 Ha·Bohr6
Miedema参数
- Miedema摩尔体积
- 19.9 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 | 1586.15 K |
| 沸点 | 3546.15 K |
氧化态分类
高级参考数据
屏蔽常数 (13)
| n | 轨道 | σ |
|---|---|---|
| 1 | s | 1.2565 |
| 2 | p | 4.2946 |
| 2 | s | 16.783 |
| 3 | d | 13.723 |
| 3 | p | 19.8508 |
| 3 | s | 20.2903 |
| 4 | d | 34.3664 |
| 4 | f | 38.9864 |
| 4 | p | 31.3532 |
| 4 | s | 30.556 |
晶体半径详情 (4)
| 电荷 | CN | 自旋 | rcrystal (pm) | 来源 |
|---|---|---|---|---|
| 3 | VI | 107.8 | from r^3 vs V plots, | |
| 3 | VII | 114 | ||
| 3 | VIII | 119.3 | from r^3 vs V plots, | |
| 3 | IX | 124.7 | from r^3 vs V plots, calculated, |
同位素衰变方式 (57)
| 同位素 | 模式 | 强度 |
|---|---|---|
| 133 | B+ | — |
| 133 | B+p | — |
| 134 | B+ | — |
| 134 | B+p | — |
| 135 | B+ | 100% |
| 135 | B+p | 2% |
| 136 | B+ | — |
| 136 | B+p | — |
| 137 | B+ | 100% |
| 137 | B+p | — |
X射线散射因子 (719)
| 能量 (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 2.59886 |
| 10.1152 | — | 2.63957 |
| 10.2317 | — | 2.68119 |
| 10.3496 | — | 2.72415 |
| 10.4688 | — | 2.7678 |
| 10.5894 | — | 2.81214 |
| 10.7114 | — | 2.8572 |
| 10.8348 | — | 2.90298 |
| 10.9596 | — | 2.94949 |
| 11.0859 | — | 2.99675 |
补充数据
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
6.2 milligrams per kilogram
参考文献 (1)
- [5] Gadolinium https://education.jlab.org/itselemental/ele064.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7×10-7 milligrams per liter
参考文献 (1)
- [5] Gadolinium https://education.jlab.org/itselemental/ele064.html
Sources
Sources of this element.
Gadolinium is found in several other minerals, including monazite and bastnasite, both of which are commercially important. With the development of ion-exchange and solvent extraction techniques, the availability and prices of gadolinium and the other rare-earth metals have greatly improved. The metal can be prepared by the reduction of the anhydrous fluoride with metallic calcium.
参考文献 (1)
- [6] Gadolinium https://periodic.lanl.gov/64.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 Gadolinium.
The element property data was retrieved from publications.