Neodymium (Nd)
lanthanideSolid
표준 원자량
144.242 u전자 배치
[Xe] 6s2 4f4녹는점
1020.85 °C끓는점
3073.85 °C밀도
7010 kg/m³산화 상태
0, +2, +3, +4전기 음성도(Pauling)
1.14제1 이온화 에너지
5.52475 eV발견 연도
1841원자 반지름
185 pm상세 정보
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.
이미지
특성
물리적 특성
- 원자 반지름(경험값)
- 185 pm 모든 원소의 원자 반지름(경험값) 비교 →
- 공유 결합 반지름
- 201 pm 모든 원소의 공유 결합 반지름 비교 →
- 반데르발스 반지름
- 229 pm 모든 원소의 반데르발스 반지름 비교 →
- 밀도
- 7010 kg/m³ 모든 원소의 밀도 비교 →
- 몰 부피
- 0.0206 L/mol
- STP에서의 상
- 고체 모든 원소의 STP에서의 상 비교 →
- 녹는점
- 1020.85 °C 모든 원소의 녹는점 비교 →
- 끓는점
- 3073.85 °C 모든 원소의 끓는점 비교 →
- 비열
- 0.19 J/(g·K) 모든 원소의 비열 비교 →
- 몰 열용량
- 27.45 J/(mol·K) 모든 원소의 몰 열용량 비교 →
- 결정 구조
- 육방 조밀 충전 모든 원소의 결정 구조 비교 →
화학적 특성
- 전기 음성도(Pauling)
- 1.14 모든 원소의 전기 음성도(Pauling) 비교 →
- 전자 친화도
- 1.913 eV
- 제1 이온화 에너지
- 5.52475 eV 모든 원소의 제1 이온화 에너지 비교 →
- 제2 이온화 에너지
- 10.783037 eV 모든 원소의 제2 이온화 에너지 비교 →
- 제3 이온화 에너지
- 22.090076 eV 모든 원소의 제3 이온화 에너지 비교 →
- 제4 이온화 에너지
- 40.60014 eV 모든 원소의 제4 이온화 에너지 비교 →
- 제5 이온화 에너지
- 60.000207 eV 모든 원소의 제5 이온화 에너지 비교 →
- 산화 상태
- 0, +2, +3, +4 모든 원소의 산화 상태 비교 →
- 원자가 전자
- 3 모든 원소의 원자가 전자 비교 →
- 전자 배치
- [Xe] 6s2 4f4
열역학적 특성
- 융해열
- 0.07400114 eV 모든 원소의 융해열 비교 →
- 기화열
- 2.829455 eV 모든 원소의 기화열 비교 →
- 승화열
- 2.995284 eV
- 원자화열
- 2.995284 eV
- 원자화 엔탈피
- 3.388091 eV
핵 특성
- 양성자 수
- 60 모든 원소의 양성자 수 비교 →
- 중성자 수
- 82 모든 원소의 중성자 수 비교 →
- 알려진 동위원소 수
- 40 모든 원소의 알려진 동위원소 수 비교 →
- 안정 동위원소 수
- 1 모든 원소의 안정 동위원소 수 비교 →
- 가장 안정한 동위원소
- Nd-142
- 발견 연도
- 1841
존재비
- 존재비(지각)
- 41.5 mg/kg 모든 원소의 존재비(지각) 비교 →
- 존재비(해양)
- 2.8 × 10−6 mg/L 모든 원소의 존재비(해양) 비교 →
결정 구조
- 격자 상수 a
- 366 pm
전자 구조
- 전자껍질별 전자 수
- 2, 8, 18, 22, 8, 2 모든 원소의 전자껍질별 전자 수 비교 →
식별자
- CAS 등록 번호
- 7440-00-8 모든 원소의 CAS 등록 번호 비교 →
- 항 기호
- 5I4
- InChI
- InChI=1S/Nd
- InChI 키
- QEFYFXOXNSNQGX-UHFFFAOYSA-N
전자 배치 측정값
Nd: 4f⁴ 6s²[Xe] 4f⁴ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁴ 6s²원자 모형
동위원소에 따라 중성자 수, 질량, 안정성은 달라지지만, 중성 원자의 전자 배치는 달라지지 않습니다.
개략적인 원자 모형이며 실제 비율과 다릅니다.
원자 지문
방출 / 흡수 스펙트럼
동위원소 분포
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 |
|---|---|---|---|
| 142 안정 | 141.907729 ± 0.000002 | 27.1520% | 안정 |
상 / 상태
이유: 녹는점(1020.85 °C)보다 995.9 °C 낮음
개략도이며 실제 비율과 다름
상전이점
전이 에너지
녹는점에서 1 mol을 녹이는 데 필요한 에너지
끓는점에서 1 mol을 기화시키는 데 필요한 에너지
승화점에서 1 mol을 승화시키는 데 필요한 에너지
밀도
표준 조건에서
표준 조건에서
원자 스펙트럼
전체 60개 중 10개를 표시합니다. 이온 전하순으로 정렬되었습니다(오름차순).
보유 에너지 준위 데이터 ?
| 이온 | 전하 | 준위 |
|---|---|---|
| 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 |
이온 반지름
| 전하 | 배위 | 스핀 | 반지름 |
|---|---|---|---|
| +2 | 8 | 해당 없음 | 129 pm |
| +2 | 9 | 해당 없음 | 135 pm |
| +3 | 6 | 해당 없음 | 98.3 pm |
| +3 | 8 | 해당 없음 | 110.9 pm |
| +3 | 9 | 해당 없음 | 116.3 pm |
| +3 | 12 | 해당 없음 | 127 pm |
화합물
동위원소 (1)
Natural neodymium is a mixture of seven stable isotopes. Fourteen other radioactive isotopes are recognized.
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 | 붕괴 방식 | |
|---|---|---|---|---|---|
| 142 안정 | 141.907729 ± 0.000002 | 27.1520% ± 0.0400% | 안정 | stable |
확장 특성
공유 결합 반지름(확장)
- 공유 결합 반지름(Pyykkö)
- 174 pm
- 공유 결합 반지름(Pyykkö, 이중 결합)
- 137 pm
반데르발스 반지름
- Alvarez
- 295 pm
- UFF
- 357.5 pm
- MM3
- 273 pm
원자 및 금속 반지름
- 원자 반지름(Rahm)
- 284 pm
번호 척도
- Mendeleev
- 19
- Pettifor
- 30
- Glawe
- 29
전기 음성도 척도
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
분극률 및 분산
- 쌍극자 분극률
- 208 a.u.
- 쌍극자 분극률(불확도)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3560 Ha·Bohr6
미데마 매개변수
- 미데마 몰 부피
- 20.58 cm3/mol
- 미데마 전자 밀도
- 2
공급 위험 및 경제성
- 생산 집중도
- 97
- 상대적 공급 위험
- 10
- 매장량 분포
- 50
- 정치적 안정성(최대 생산국)
- 24
- 정치적 안정성(최대 매장국)
- 24
상전이 및 동소체
| 녹는점 | 1289.15 K |
| 끓는점 | 3347.15 K |
산화 상태 분류
심화 참고 데이터
차폐 상수 (13)
| n | 오비탈 | 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 |
결정 반지름 상세 정보 (6)
| 전하 | CN | 스핀 | rcrystal (pm) | 기원 |
|---|---|---|---|---|
| 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, |
동위원소 붕괴 방식 (52)
| 동위원소 | 모드 | 세기 |
|---|---|---|
| 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% |
X선 산란 인자 (508)
| 에너지 (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 |
추가 데이터
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.15×101 milligrams per kilogram
참고 문헌 (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
참고 문헌 (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.
참고 문헌 (1)
- [6] Neodymium https://periodic.lanl.gov/60.shtml
참고 문헌
(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.