Neodymium (Nd)
lanthanideSolid
标准原子量
144.242 u电子排布
[Xe] 6s2 4f4熔点
1020.85 °C沸点
3073.85 °C密度
7010 kg/m³氧化态
0, +2, +3, +4电负性（鲍林）
1.14第一电离能
5.52475 eV发现年份
1841原子半径
185 pm详细信息
Neodymium is a light lanthanide metal and one of the more abundant rare-earth elements. It occurs in minerals with other lanthanides rather than as a native element. Its chemistry is dominated by the trivalent ion Nd³⁺, which gives many salts and glasses a pink to violet color. Technologically, neodymium is most important in high-strength permanent magnets and in optically active glasses and crystals.
The metal has a bright silvery metallic luster, Neodymium is one of the more reactive rare-earth metals and quickly tarnishes in air, forming an oxide that spalls off and exposes metal to oxidation. The metal, therefore, should be kept under light mineral oil or sealed in a plastic material. Neodymium exists in two allotropic forms, with a transformation from a double hexagonal to a body-centered cubic structure taking place at 863°C.
The name derives from the Greek neos for "new" and didymos for "twin". It was discovered by the Swedish surgeon and chemist Carl Gustav Mosander in 1841, who called it didymium (or twin) because of its similarity to lanthanum, which he had previously discovered two years earlier. In 1885, the Austrian chemist Carl Auer (Baron von Welsbach) separated didymium into two elements, one of which he called neodymium (or new twin).
Neodymium was discovered by Carl F. Auer von Welsbach, an Austrian chemist, in 1885. He separated neodymium, as well as the element praseodymium, from a material known as didymium. Today, neodymium is primarily obtained from through an ion exchange process monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements.
From the Greek word neos meaning new, and didymos, twin. In 1841, Mosander, extracted a rose-colored oxide from cerite , which he believed contained a new element. He named the element didymium, as it was an inseparable twin brother of lanthanum. In 1885 von Welsbach separated didymium into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is in misch metal, long known and used as a pyrophoric alloy for light flints, the element was not isolated in relatively pure form until 1925. Neodymium is present in misch metal to the extent of about 18%. It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals.
Pure neodymium is a bright, silvery metal when freshly cut, but it tarnishes in air as an oxide layer forms. It is relatively soft and can be cut with a knife. The metal slowly reacts with moisture and oxidizes more rapidly when finely divided or heated.
The largest use of neodymium is in neodymium-iron-boron permanent magnets, commonly based on the Nd₂Fe₁₄B phase. These magnets are used in electric motors, generators, hard-disk drives, loudspeakers, sensors, and magnetic couplings. Neodymium-doped yttrium aluminium garnet, Nd:Y₃Al₅O₁₂, is a major solid-state laser material. Neodymium compounds are also used to color and filter glass, including didymium-type eyewear for glassworking.
Neodymium makes up about 18% of Misch metal, a material that is used to make flints for lighters. Neodymium is also a component of didymium glass, which is used to make certain types of welder's and glass blower's goggles. Neodymium is added to glass to remove the green color caused by iron contaminants. It can also be added to glass to create violet, red or gray colors. Some types of glass containing neodymium are used by astronomers to calibrate devices called spectrometers and other types are used to create artificial rubies for lasers. Some neodymium salts are used to color enamels and glazes.
Didymium, of which neodymium is a component, is used for coloring glass to make welders goggles. By itself, neodymium colors glass delicate shades ranging from pure violet through wine-red and warm gray. Light transmitted through such glass shows unusually sharp absorption bands. The glass has been used in astronomical work to produce sharp bands by which spectral lines may be calibrated. Glass containing neodymium can be used as a laser material to produce coherent light. Neodymium salts are also used as a colorant for enamels.
Isotopes in Geochronology
143Nd is a radiogenic isotope produced by decay of 147Sm, with a half-life of 1.06×1011 years. Thus, the isotope-amount ratio n(143Nd)/n(144Nd) can be used for dating rocks on long time scales and as a chemical tracer in geochemistry (Fig. IUPAC.60.1) [427] M. T. McCullocha, M. R. Perfita. Earth. Planet. Sci. Lett.56, 167 (1981)., [428] R. Eichhorn, R. Höll, E. Jagoutz, U. Schärer. Geochim. Cosmochim. Acta61, 5005 (1997).. The very small accumulation of 142Nd in billion-year-old metamorphosed rocks from Greenland [from the relatively short-lived (about 68×106 years) alpha decay of 146Sm] provided evidence that the crust of the Earth formed before the young planet was more than 100×106 years old. This is because only a short amount of time could have elapse to incorporate the 146Sm parent radionuclide into the ancient Greenland minerals before it decayed [429] M. G. Jackson, S. R. Hart, A. A. P. Koppers, H. Staudigel, J. Konter, J. Blusztajn, M. Kurz, J. A. Russell. Nature448, 684 (2007)., [430] G. Caro, B. Bourdon, J. L. Birck, S. Moorbath. Nature423, 428 (2003)..
Isotopes Used as a Source of Radioactive Isotope(s)
146Nd has been used in the production of 147Pm (with a half-life of 2.6 years), via the reaction 146Nd (n, γ) 147Nd, which is followed by a subsequent electron decay reaction, 147Nd→ 147Pm+β - reaction. 147Pm is a radioactive power-generation source [431] C. S. Lee, Y. M. Wang, W. L. Cheng, G. Ting. J. Radioanal. Nucl. Chem.130, 21 (1988)..
Neodymium most commonly forms compounds in the +3 oxidation state, and Nd³⁺ salts are typically pale pink, rose, lavender, or violet depending on ligand and hydration. Important compounds include neodymium(III) oxide, Nd₂O₃, neodymium(III) chloride, NdCl₃, and neodymium(III) fluoride, NdF₃. The oxide is a common intermediate in separation and materials production. Divalent neodymium is known in some solid-state compounds, but it is much less stable and far less common than Nd³⁺ chemistry.
See more information at the Neodymium compound page.
Bulk neodymium metal has low acute toxicity but is reactive as a fine powder and can present a fire hazard. Dusts and soluble salts should be handled as industrial chemical hazards because rare-earth compounds can irritate the eyes, skin, and respiratory tract. Strong neodymium magnets create mechanical hazards: they can pinch skin, shatter on impact, damage magnetic media, and interfere with some implanted medical devices.
Neodymium has a low-to-moderate acute toxic rating. As with other rare earths, neodymium should be handled with care.
Neodymium is widely dispersed in the crust, mainly in rare-earth minerals such as monazite and bastnäsite. In natural waters it is present at very low concentrations and tends to bind to particles, phosphates, carbonates, and organic matter rather than remain as a free ion. Mining and processing can disturb soils and generate waste streams containing other rare earths, thorium, uranium, acids, or salts, depending on the ore and process.
Neodymium is produced by mining rare-earth ores, separating mixed lanthanides through solvent extraction or ion-exchange processes, and reducing suitable halides or oxides to metal when needed. Demand is strongly tied to Nd-Fe-B magnets, often with praseodymium partly substituting for neodymium and dysprosium or terbium added for high-temperature performance. Supply is constrained by the difficulty of separating similar lanthanides and by the environmental controls needed for ore processing. Recycling from magnets is technically possible and increasing, but collection and separation remain limiting factors.
Made from electrolysis of its halide salts, which are made from monazite sand.
Neodymium is produced mainly by neutron-capture nucleosynthesis in evolved stars and stellar explosions, with contributions from both slow and rapid neutron-capture processes. It is less abundant than lighter elements but is a normal trace constituent of the Solar System. Meteorites and planetary rocks contain neodymium in rare-earth patterns useful for geochemical and isotopic studies.
- The name neodymium means “new twin,” reflecting its separation from didymium.
- Natural neodymium consists of several stable isotopes and very long-lived radioactive ¹⁴⁴Nd and ¹⁵⁰Nd.
- Neodymium glass can appear different colors under different lighting because of sharp f-electron absorption bands.
- Nd-Fe-B magnets are usually coated because the alloy corrodes readily.
- Samarium-cobalt magnets tolerate heat better, but Nd-Fe-B magnets usually provide stronger fields for their size.
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
- 201 pm 比较所有元素的共价半径 →
- 范德华半径
- 229 pm 比较所有元素的范德华半径 →
- 密度
- 7010 kg/m³ 比较所有元素的密度 →
- 摩尔体积
- 0.0206 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
- 1020.85 °C 比较所有元素的熔点 →
- 沸点
- 3073.85 °C 比较所有元素的沸点 →
- 比热容
- 0.19 J/(g·K) 比较所有元素的比热容 →
- 摩尔热容
- 27.45 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）
- 1.14 比较所有元素的电负性（鲍林） →
- 电子亲和能
- 1.913 eV
- 第一电离能
- 5.52475 eV 比较所有元素的第一电离能 →
- 第二电离能
- 10.783037 eV 比较所有元素的第二电离能 →
- 第三电离能
- 22.090076 eV 比较所有元素的第三电离能 →
- 第四电离能
- 40.60014 eV 比较所有元素的第四电离能 →
- 第五电离能
- 60.000207 eV 比较所有元素的第五电离能 →
- 氧化态
- 0, +2, +3, +4 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 4f4
热力学性质
- 熔化热
- 0.07400114 eV 比较所有元素的熔化热 →
- 汽化热
- 2.829455 eV 比较所有元素的汽化热 →
- 升华热
- 2.995284 eV
- 原子化热
- 2.995284 eV
- 原子化焓
- 3.388091 eV
核性质
- 质子
- 60 比较所有元素的质子 →
- 中子
- 82 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
- 1 比较所有元素的稳定同位素 →
- 最稳定同位素
- Nd-142
- 发现年份
- 1841
丰度
- 丰度（地壳）
- 41.5 mg/kg 比较所有元素的丰度（地壳） →
- 丰度（海洋）
- 2.8 × 10−6 mg/L 比较所有元素的丰度（海洋） →
晶体结构
- 晶格常数a
- 366 pm
电子结构
- 各电子层电子数
- 2, 8, 18, 22, 8, 2 比较所有元素的各电子层电子数 →
标识符
- CAS登记号
- 7440-00-8 比较所有元素的CAS登记号 →
- 谱项符号
- 5I4
- InChI
- InChI=1S/Nd
- InChI Key
- QEFYFXOXNSNQGX-UHFFFAOYSA-N
电子排布 实测值
Nd: 4f⁴ 6s²[Xe] 4f⁴ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁴ 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 |
|---|---|---|---|
| 142 稳定 | 141.907729 ± 0.000002 | 27.1520% | 稳定 |
物相 / 状态
原因: 低于熔点（1020.85 °C）995.9 °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60项。 按离子电荷升序排列。
收录能级 ?
| 离子 | 电荷 | 能级 |
|---|---|---|
| Nd I | 0 | 739 |
| Nd II | +1 | 840 |
| Nd III | +2 | 31 |
| Nd IV | +3 | 19 |
| Nd V | +4 | 2 |
| Nd VI | +5 | 2 |
| Nd VII | +6 | 2 |
| Nd VIII | +7 | 2 |
| Nd IX | +8 | 2 |
| Nd X | +9 | 2 |
离子半径
| 电荷 | 配位 | 自旋 | 半径 |
|---|---|---|---|
| +2 | 8 | 暂无 | 129 pm |
| +2 | 9 | 暂无 | 135 pm |
| +3 | 6 | 暂无 | 98.3 pm |
| +3 | 8 | 暂无 | 110.9 pm |
| +3 | 9 | 暂无 | 116.3 pm |
| +3 | 12 | 暂无 | 127 pm |
化合物
同位素 (1)
Natural neodymium is a mixture of seven stable isotopes. Fourteen other radioactive isotopes are recognized.
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 | 衰变方式 | |
|---|---|---|---|---|---|
| 142 稳定 | 141.907729 ± 0.000002 | 27.1520% ± 0.0400% | 稳定 | stable |
扩展性质
共价半径（扩展）
- 共价半径（Pyykkö）
- 174 pm
- 共价半径（Pyykkö，双键）
- 137 pm
范德华半径
- Alvarez
- 295 pm
- UFF
- 357.5 pm
- MM3
- 273 pm
原子半径与金属半径
- 原子半径（Rahm）
- 284 pm
编号标度
- Mendeleev
- 19
- Pettifor
- 30
- Glawe
- 29
电负性标度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
极化率与色散
- 偶极极化率
- 208 a.u.
- 偶极极化率（不确定度）
- 20 a.u.
- C₆ (Gould–Bučko)
- 3560 Ha·Bohr6
Miedema参数
- Miedema摩尔体积
- 20.58 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 | 1289.15 K |
| 沸点 | 3347.15 K |
氧化态分类
高级参考数据
屏蔽常数 (13)
| n | 轨道 | σ |
|---|---|---|
| 1 | s | 1.1868 |
| 2 | p | 4.2434 |
| 2 | s | 15.7838 |
| 3 | d | 13.8432 |
| 3 | p | 19.311 |
| 3 | s | 19.6572 |
| 4 | d | 33.1908 |
| 4 | f | 37.734 |
| 4 | p | 29.986 |
| 4 | s | 29.0136 |
晶体半径详情 (6)
| 电荷 | CN | 自旋 | rcrystal (pm) | 来源 |
|---|---|---|---|---|
| 2 | VIII | 143 | ||
| 2 | IX | 149 | ||
| 3 | VI | 112.3 | from r^3 vs V plots, | |
| 3 | VIII | 124.9 | from r^3 vs V plots, | |
| 3 | IX | 130.3 | from r^3 vs V plots, | |
| 3 | XII | 141 | estimated, |
同位素衰变方式 (52)
| 同位素 | 模式 | 强度 |
|---|---|---|
| 124 | B+ | — |
| 124 | B+p | — |
| 125 | B+ | 100% |
| 125 | B+p | 0% |
| 126 | B+ | — |
| 126 | B+p | — |
| 127 | B+ | 100% |
| 127 | B+p | — |
| 128 | B+ | — |
| 129 | B+ | 100% |
X射线散射因子 (508)
| 能量 (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.24448 |
| 10.1617 | — | 0.25177 |
| 10.3261 | — | 0.25926 |
| 10.4931 | — | 0.26698 |
| 10.6628 | — | 0.27494 |
| 10.8353 | — | 0.28312 |
| 11.0106 | — | 0.29156 |
| 11.1886 | — | 0.30024 |
| 11.3696 | — | 0.30918 |
| 11.5535 | — | 0.31839 |
补充数据
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.15×101 milligrams per kilogram
参考文献 (1)
- [5] Neodymium https://education.jlab.org/itselemental/ele060.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
2.8×10-6 milligrams per liter
参考文献 (1)
- [5] Neodymium https://education.jlab.org/itselemental/ele060.html
Production
Production of this element (from raw materials or other compounds containing the element).
The element may be obtained by separating neodymium salts from other rare earths by ion-exchange or solvent extraction techniques, and by reducing anhydrous halides such as NdF3 with calcium metal. Other separation techniques are possible.
参考文献 (1)
- [6] Neodymium https://periodic.lanl.gov/60.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 Neodymium.
The element property data was retrieved from publications.