Terbium (Tb)
lanthanideSolid
標準原子量
158.92535 u電子配置
[Xe] 6s2 4f9融点
1355.85 °C沸点
3229.85 °C密度
8230 kg/m³酸化数
0, +1, +2, +3, +4電気陰性度（Pauling）
データなし第1イオン化エネルギー
5.8638 eV発見年
1843原子半径
175 pm詳細
Terbium is a lanthanide rare-earth metal with atomic number 65. It is chemically similar to neighboring gadolinium and dysprosium and occurs in minerals with other rare earths rather than as a native element. Its most distinctive technological role comes from Tb³⁺ luminescence, which gives intense green emission in suitable host materials, and from the large magnetostrictive response of terbium-containing alloys.
Terbium is reasonably stable in air. It is a silver-gray metal, and is malleable, ductile, and soft enough to be cut with a knife. Two crystal modifications exist, with a transformation temperature of 1289°C. Twenty one isotopes with atomic masses ranging from 145 to 165 are recognized. The oxide is a chocolate or dark maroon color.
The name derives from the village of Ytterby in Sweden, where the mineral ytterbite (the source of terbium) was first found. Terbium was discovered by the Swedish surgeon and chemist Carl-Gustav Mosander in 1843 in an yttrium salt, which he resolved into three elements. He called one yttrium, a rose-colored salt he called terbium, and a deep-yellow peroxide he called erbium. In 1862, the Swiss chemist Marc Delafontaine reexamined yttrium and found the yellow peroxide. Because the name erbium had now been assigned to the rose-colored oxide, he reintroduced the name terbium for the yellow peroxide. Thus the original names given to erbium and terbium samples are now switched.
The mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10), discovered in a quarry near the town of Ytterby, Sweden, has been the source of a great number of rare earth elements. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into three materials, which he named yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia and, by 1877, had reversed their names. What Mosander called erbia is now called terbia and visa versa. From these two substances, Mosander discovered two new elements, terbium and erbium. Today, terbium can be obtained from the minerals xenotime (YPO4) and euxenite ((Y, Ca, Er, La, Ce, U, Th)(Nb, Ta, Ti)2O6), but is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements that typically contains as much as 0.03% terbium.
Discovered by Mosander in 1843. Terbium is a member of the lanthanide or "rare earth" group of elements. It is found in cerite, gadolinite, and other minerals along with other rare earths. It is recovered commercially from monazite in which it is present to the extent of 0.03%, from xenotime, and from euxenite, a complex oxide containing 1% or more of terbia.
Pure terbium is a soft, silvery-gray metal. It is malleable enough to be cut and, like many lanthanides, slowly tarnishes in air as surface oxides form. It has more than one solid allotrope, with a structural change at elevated temperature.
Terbium is used mainly in small amounts where its optical or magnetic properties are valuable. Tb³⁺ activators provide green emission in phosphors for lighting, displays, and some X-ray imaging materials. Terbium is also a component of Terfenol-D, a terbium-dysprosium-iron magnetostrictive alloy used in actuators, sonar transducers, and vibration-control devices. In research and specialized instruments, terbium compounds are used as luminescent probes and magnetic materials.
Terbium is used to dope some types of solid-state devices and, along with zirconium dioxide (ZrO2), as a crystal stabilizer in fuel cells that operate at high temperatures.
Terbia, the renamed material that Mosander discovered in 1843, is terbium oxide (Tb2O3), one of terbium's compounds. Terbia can potentially be used as an activator for green phosphors in television tubes. Sodium terbium borate, another terbium compound, is used to make laser light.
Sodium terbium borate is used in solid-state devices. It can be used with ZrO2 as a crystal stabilizer of fuel cells which operate at elevated temperature. Few other uses have been found.
Isotopes in Medicine
149Tb (with a half-life of 4.1 h) is being used in targeted radiotherapy using alpha particles for labeling radioimmunoconjugates in cancer treatments [458] N. G. Zaitseva, S. N. Dmitriev, O. D. Maslov, L. G. Molokanova, G. Y. Starodub, S. V. Shishkin, T. V. Shishkina, G. J. Beyer. Czech. J. Phys. Suppl.53, A455 (2003)., [459] G. J. Beyer, M. Miederer, S. Vranjes-Duric, J. J. Comor, G. Kunzi, O. Hartley, R. Senekowitsch-Schmidtke, D. Soloviev, F. Buchegger. Eur. J. Nucl. Med. Mol. Imaging31, 547 (2004).. 161Tb (with a half-life of 6.9 days) attached to a bioconjugate (two covalently linked molecules, one or more of which is a biomolecule), is being used in cancer therapy as a targeted radiation treatment of cancer cells [459] G. J. Beyer, M. Miederer, S. Vranjes-Duric, J. J. Comor, G. Kunzi, O. Hartley, R. Senekowitsch-Schmidtke, D. Soloviev, F. Buchegger. Eur. J. Nucl. Med. Mol. Imaging31, 547 (2004)., [460] S. Lehenberger, C. Barkhausen, S. Cohrs, E. Fischer, J. Grünberg, A. Hohn, U. Köster, R. Schibli, A. Türler, K. Zhernosekov. Nucl. Med. Biol.38, 917 (2011).. 161Tb is being used for imaging as it allows for on-line monitoring of its distribution using gamma cameras [460] S. Lehenberger, C. Barkhausen, S. Cohrs, E. Fischer, J. Grünberg, A. Hohn, U. Köster, R. Schibli, A. Türler, K. Zhernosekov. Nucl. Med. Biol.38, 917 (2011).. 149Tb is produced by the reaction 142Nd(12C,5n) 149Dy, which is followed by a subsequent positron decay reaction 149Dy→ 149Tb+β +. It can also be produced by the reaction 141Pr(12C,4n) 149Tb; beam geometry is important for satisfactory yield of 149Tb (Fig. IUPAC.65.1) [461] S. Sarkar, B. J. Allen, S. Imam, G. Goozee, J. Leigh, H. Meriaty. “Production and separation of terbium-149,152 for targeted cancer therapy”, in Second international conference on isotopes; Sydney, NSW (Australia); 273 p. Conference proceedings, 12–16 Oct 1997, C. J. Hardy (Ed.), Australian Nuclear Association Inc., Sutherland, NSW (Australia), pp. 206–211..
Terbium most commonly forms trivalent compounds containing Tb³⁺. Representative materials include terbium(III) oxide, Tb₂O₃, terbium(III) chloride, TbCl₃, and terbium(III) fluoride, TbF₃. Unlike many lanthanides, terbium also has accessible tetravalent chemistry in strongly oxidizing oxide and fluoride environments; terbium(IV) oxide, TbO₂, is a well established example. Mixed-valence oxides and doped host lattices are important because they tune luminescence, oxygen storage, and magnetic behavior.
See more information at the Terbium compound page.
Metallic terbium is not highly toxic in ordinary handling, but powders can be a fire and dust hazard, and soluble terbium salts should be treated as harmful laboratory chemicals. Fine metal reacts more readily with air and moisture than bulk pieces. Terbium has no known biological role. Commercial terbium is essentially stable isotopically; radiological hazards apply only to artificially produced radioactive isotopes or activated materials.
Little is known of the toxicity of terbium. It should be handled with care as with other lanthanide element
Terbium is a dispersed lithophile element found in rare-earth minerals such as monazite, bastnäsite, xenotime, and ion-adsorption clays. In soils and waters it is generally immobile because Tb³⁺ binds strongly to phosphates, carbonates, oxides, and organic matter. Natural concentrations are low, and biological uptake is limited. Environmental concern is usually associated with mining, acid leaching, and waste handling rather than with terbium metal itself.
Terbium is produced as a separated rare-earth product, not mined alone. Ores and concentrates are processed to dissolve mixed rare earths, then solvent extraction or ion exchange separates terbium from chemically similar lanthanides. Supply is constrained by the low abundance of terbium in many deposits, the complexity of separation, and dependence on rare-earth refining capacity. Demand is driven by phosphors and magnetostrictive alloys, but use per device is usually small. Recycling is technically possible from phosphor powders and some magnets or alloys, yet collection and separation are often limiting.
Found with other rare earths in monazite sand, which typically contain 0.03% terbium. Other sources are xenotime and euxenite, both of which are oxide mixtures that can contain up to 1% terbium.
Terbium is a heavy rare-earth element made mainly by neutron-capture nucleosynthesis in earlier generations of stars, with contributions from slow and rapid neutron-capture processes. It is far less abundant cosmically than iron-group elements and lighter rock-forming elements. In planetary materials it follows other trivalent lanthanides and concentrates in refractory mineral phases rather than volatile reservoirs.
- Terbium has only one stable natural isotope, ¹⁵⁹Tb.
- Its name comes from Ytterby, the Swedish locality linked to several rare-earth element names.
- Tb³⁺ emission is commonly used as a green reference in luminescence spectroscopy.
- Terfenol-D takes its name from terbium, iron, Naval Ordnance Laboratory, and dysprosium.
- Terbium can form stable Tb⁴⁺ in oxides more readily than most lanthanides.
画像
性質
物理的性質
- 原子半径（経験値）
- 175 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 194 pm 全元素の共有結合半径を比較 →
- ファンデルワールス半径
- 221 pm 全元素のファンデルワールス半径を比較 →
- 密度
- 8230 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.0192 L/mol
- 標準温度・圧力（STP）での相
- 固体 全元素の標準温度・圧力（STP）での相を比較 →
- 融点
- 1355.85 °C 全元素の融点を比較 →
- 沸点
- 3229.85 °C 全元素の沸点を比較 →
- 熱伝導率
- 11.1 W/(m·K) 全元素の熱伝導率を比較 →
- 比熱容量
- 0.182 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 28.91 J/(mol·K) 全元素のモル熱容量を比較 →
- 結晶構造
- 六方最密充填構造 全元素の結晶構造を比較 →
化学的性質
- 電子親和力
- 1.124 eV
- 第1イオン化エネルギー
- 5.8638 eV 全元素の第1イオン化エネルギーを比較 →
- 第2イオン化エネルギー
- 11.51304 eV 全元素の第2イオン化エネルギーを比較 →
- 第3イオン化エネルギー
- 21.820075 eV 全元素の第3イオン化エネルギーを比較 →
- 第4イオン化エネルギー
- 39.330135 eV 全元素の第4イオン化エネルギーを比較 →
- 第5イオン化エネルギー
- 66.500229 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- 0, +1, +2, +3, +4 全元素の酸化数を比較 →
- 価電子
- 3 全元素の価電子を比較 →
- 電子配置
- [Xe] 6s2 4f9
熱力学的性質
- 融解熱
- 0.1119345 eV 全元素の融解熱を比較 →
- 蒸発熱
- 3.016013 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 4.031715 eV
- 原子化熱
- 4.031715 eV
- 原子化エンタルピー
- 4.028605 eV
原子核
- 陽子数
- 65 全元素の陽子数を比較 →
- 中性子数
- 94 全元素の中性子数を比較 →
- 既知の同位体
- 40 全元素の既知の同位体を比較 →
- 安定同位体
- 1 全元素の安定同位体を比較 →
- 最も安定な同位体
- Tb-159
- 発見年
- 1843
存在度
- 存在度（地殻）
- 1.2 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 1.4 × 10−7 mg/L 全元素の存在度（海洋）を比較 →
結晶構造
- 格子定数a
- 360 pm
電子構造
- 各電子殻の電子数
- 2, 8, 18, 27, 8, 2 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7440-27-9 全元素のCAS登録番号を比較 →
- 項記号
- 6H°15/2
- InChI
- InChI=1S/Tb
- InChI Key
- GZCRRIHWUXGPOV-UHFFFAOYSA-N
電子配置 測定値
Tb: 4f⁹ 6s²[Xe] 4f⁹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁹ 6s²原子モデル
同位体によって中性子数、質量、安定性は変わりますが、中性原子の電子配置は変わりません。
模式的な原子モデルです。実際の縮尺とは異なります。
原子の指紋
発光／吸収スペクトル
同位体分布
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 |
|---|---|---|---|
| 159 安定 | 158.9253547 ± 0.0000019 | 100.0000% | 安定 |
相／状態
理由: 融点（1355.85 °C）より1330.8 °C低い
模式図、実際の縮尺とは異なります
相転移点
相転移エネルギー
融点で1 molを融解させるのに必要なエネルギー
沸点で1 molを蒸発させるのに必要なエネルギー
昇華点で1 molを昇華させるのに必要なエネルギー
密度
標準条件下
標準条件下
原子スペクトル
全65件中10件を表示しています。 イオンの電荷の昇順で並べています。
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Tb I | 0 | 600 |
| Tb II | +1 | 154 |
| Tb III | +2 | 125 |
| Tb IV | +3 | 26 |
| Tb V | +4 | 2 |
| Tb VI | +5 | 2 |
| Tb VII | +6 | 2 |
| Tb VIII | +7 | 2 |
| Tb IX | +8 | 2 |
| Tb X | +9 | 2 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +3 | 6 | データなし | 92.30000000000001 pm |
| +3 | 7 | データなし | 98 pm |
| +3 | 8 | データなし | 104 pm |
| +3 | 9 | データなし | 109.5 pm |
| +4 | 6 | データなし | 76 pm |
| +4 | 8 | データなし | 88 pm |
化合物
同位体 (1)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 159 安定 | 158.9253547 ± 0.0000019 | 100.0000% | 安定 | stable |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 168 pm
- 共有結合半径（Pyykkö、二重結合）
- 135 pm
ファンデルワールス半径
- Alvarez
- 279 pm
- UFF
- 345.1 pm
- MM3
- 270 pm
原子半径と金属半径
- 原子半径（Rahm）
- 276 pm
番号付けの尺度
- Mendeleev
- 29
- Pettifor
- 26
- Glawe
- 25
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 3
分極率と分散
- 双極子分極率
- 170 a.u.
- 双極子分極率（不確かさ）
- 20 a.u.
- C₆ (Gould–Bučko)
- 2590 Ha·Bohr6
ミーデマパラメータ
- ミーデマモル体積
- 19.32 cm3/mol
- ミーデマ電子密度
- 2
供給リスクと経済性
- 生産集中度
- 97
- 相対供給リスク
- 10
- 埋蔵量の分布
- 50
- 政治的安定性（最大生産国）
- 24
- 政治的安定性（最大埋蔵国）
- 24
相転移と同素体
| 融点 | 1632.15 K |
| 沸点 | 3503.15 K |
酸化数の分類
専門参考データ
遮蔽定数 (13)
| n | 軌道 | σ |
|---|---|---|
| 1 | s | 1.2739 |
| 2 | p | 4.3076 |
| 2 | s | 17.0278 |
| 3 | d | 13.7015 |
| 3 | p | 19.9853 |
| 3 | s | 20.4485 |
| 4 | d | 34.69 |
| 4 | f | 39.1352 |
| 4 | p | 31.6012 |
| 4 | s | 30.98 |
結晶半径の詳細 (6)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 3 | VI | 106.3 | from r^3 vs V plots, | |
| 3 | VII | 112 | estimated, | |
| 3 | VIII | 118 | from r^3 vs V plots, | |
| 3 | IX | 123.5 | from r^3 vs V plots, | |
| 4 | VI | 90 | from r^3 vs V plots, | |
| 4 | VIII | 102 |
同位体の崩壊形式 (63)
| 同位体 | モード | 強度 |
|---|---|---|
| 135 | p | 100% |
| 135 | B+ | — |
| 136 | B+ | — |
| 136 | B+p | — |
| 137 | p | — |
| 137 | B+ | — |
| 138 | B+ | — |
| 138 | B+p | — |
| 138 | p | 0% |
| 139 | B+ | 100% |
X線散乱因子 (514)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.15974 |
| 10.1617 | — | 0.16625 |
| 10.3261 | — | 0.17301 |
| 10.4931 | — | 0.18005 |
| 10.6628 | — | 0.18738 |
| 10.8353 | — | 0.19501 |
| 11.0106 | — | 0.20295 |
| 11.1886 | — | 0.21121 |
| 11.3696 | — | 0.21981 |
| 11.5535 | — | 0.22823 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.2 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.4×10-7 milligrams per liter
参考文献 (1)
Production
Production of this element (from raw materials or other compounds containing the element).
Terbium has been isolated only in recent years with the development of ion-exchange techniques for separating the rare-earth elements. As with other rare earth metals, it can be produced by reducing the anhydrous chloride or fluoride with calcium metal in a tantalum crucible. Calcium and tantalum impurities can be removed by vacuum remelting. Other methods of isolation are possible.
参考文献 (1)
- [6] Terbium https://periodic.lanl.gov/65.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 Terbium.
The element property data was retrieved from publications.