Thulium (Tm)
lanthanideSolid
標準原子量
168.93422 u電子配置
[Xe] 6s2 4f13融点
1544.85 °C沸点
1949.85 °C密度
9320 kg/m³酸化数
0, +1, +2, +3電気陰性度（Pauling）
1.25第1イオン化エネルギー
6.184402 eV発見年
1879原子半径
175 pm詳細
Thulium is a lanthanide rare-earth metal and the least abundant stable lanthanide in Earth’s crust. It is chemically typical of the series, forming mainly Tm³⁺ compounds with a high affinity for oxygen and halogens. The element is not scarce enough to be unattainable, but it is dispersed and difficult to separate from neighboring lanthanides. Its technological importance is concentrated in isotope sources, specialty lasers, and optical materials rather than bulk structural use.
Thulium can be isolated by reduction of the oxide with lanthanum metal or by calcium reduction of a closed container. The element is silver-gray, soft, malleable, and ductile, and can be cut with a knife. Twenty five isotopes are known, with atomic masses ranging from 152 to 176. Natural thulium, which is 100% 169Tm, is stable.
The name derives from Thule, the earliest name for the northernmost part of the civilized world—Scandinavia. It was discovered in 1879 by the Swedish chemist Per Theodor Cleve in a sample of erbium mineral. Thulium was first isolated by the American chemist Charles James in 1911.
Thulium was discovered by Per Theodor Cleve, a Swedish chemist, in 1879. Cleve used the same method Carl Gustaf Mosander used to discover lanthanum, erbium and terbium, he looked for impurities in the oxides of other rare earth elements. He started with erbia, the oxide of erbium (Er2O3), and removed all of the known contaminants. After further processing, he obtained two new materials, one brown and the other green. Cleve named the brown material holmia and the green material thulia. Holmia is the oxide of the element holmium and thulia is the oxide of the element thulium. Today, thulium 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 can contain as much as 0.007% thulium.
Named after Thule, the earliest name for Scandinavia. Discovered in 1879 by Cleve. Thulium occurs in small quantities along with other rare earths in a number of minerals. It is obtained commercially from monazite, which contains about 0.007% of the element. Thulium is the least abundant of the rare earth elements, but with new sources recently discovered, it is now considered to be about as rare as silver,gold, or cadmium.
Pure thulium is a soft, malleable, silvery metal. It slowly tarnishes in air as oxide forms on the surface and reacts more readily when heated. Like many lanthanides, it can be cut with a knife and is normally stored to limit oxidation.
Thulium has specialized uses where its nuclear or optical properties are useful. Neutron-activated ¹⁷⁰Tm produces ¹⁷⁰Tm, a portable gamma and X-ray source formerly used in industrial radiography and still of technical interest where compact sealed sources are suitable. Thulium-doped yttrium aluminium garnet, commonly written Y₃Al₅O₁₂:Tm, and other host crystals are used in solid-state lasers near the two-micrometre infrared region. Thulium-doped silica fibers are also used in fiber lasers and amplifiers. Small amounts may be used in research alloys and magnetic studies, but there is no large-volume elemental application.
Thulium is the least abundant of the naturally occurring rare earth elements. Metallic thulium is relatively expensive and has only recently become available. It currently has no commercial applications, although one of its isotopes, thulium-169, could be used as a radiation source for portable X-ray machines.
Thulium forms no commercially important compounds. Some of thulium's compounds include: thulium oxide (Tm2O3), thulium fluoride (TmF3) and thulium iodide (TmI3).
Because of the relatively high price of the metal, thulium has not yet found many practical applications. 169Tm bombarded in a nuclear reactor can be used as a radiation source in portable X-ray equipment. 171Tm is potentially useful as an energy source. Natural thulium also has possible use in ferrites (ceramic magnetic materials) used in microwave equipment, and can be used for doping fiber lasers. As with other lanthanides, thulium has a low-to-moderate acute toxic rating. It should be handled with care.
Isotopes in Industry
170Tm (with a half-life of about 130 days) is used in the petrochemical industry for industrial radiography to test welds in pipes and tanks [486] Industrial Applications of Sealed Radiation Sources and Alternative Non Nuclear Technologies, Final Report, 68-D-00-210, p. 37. Trinity Engineering Associates Ohio (2002)..
Isotopes in Medicine
167Tm (with a half-life of 9.2 days) is useful for tumor and bone studies [487] F. Tárkányi, A. Hermanne, S. Takács, B. Király, I. Spahn, A. V. Ignatyuk. Appl. Radiat. Isot.68, 250 (2010).. Stable 169Tm can be bombarded in a nuclear reactor to create 170Tm, via the 169Tm (n, γ) 170Tm reaction, which emits X-rays and has been used in portable X-ray equipment as a radiation source [488] D. Granero, J. Pérez-Calatayud, F. Ballester, A. J. Bos, J. Venselaar. Radiat. Prot. Dosimetry118, 11 (2006).. 170Tm has been used in high-dose-rate (HDR) brachytherapy [489] F. Ballester, D. Granero, J. Perez-Calatayud, J. L. Venselaar, M. J. Rivard. Med. Phys.37, 1629 (2010). and for use in radiosynovectomy of medium sized joints (Fig. IUPAC.69.1) [490] A. Polyak, T. Das, S. Chakraborty, R. Kiraly, G. Dabasi, R. P. Joba, C. Jakab, J. Thuroczy, Z. Postenyi, V. Haasz, G. Janoki, G. A. Janoki, M. R. A. Pillai, L. Balogh. Cancer Biother. Radiopharm.29, 330 (2014)..
Thulium chemistry is dominated by the +3 oxidation state. Thulium(III) oxide, Tm₂O₃, is the common oxide and is a useful starting material for preparing other salts and optical ceramics. Thulium(III) chloride, TmCl₃, and thulium(III) fluoride, TmF₃, are representative halides; the fluoride is sparingly soluble and useful in separations and fluoride materials. A +2 state is known in some strongly reducing solid compounds, but it is much less stable than Tm³⁺ in ordinary aqueous chemistry. In solution, Tm³⁺ salts are typically pale green to nearly colorless depending on concentration and ligand field.
See more information at the Thulium compound page.
Metallic thulium has low acute chemical toxicity compared with many heavy metals, but fine powder is a fire hazard and can react with air or moisture. Soluble thulium salts should be handled as toxic laboratory chemicals because rare-earth ions can affect biological processes at elevated exposure. Radioactive ¹⁷⁰Tm presents an external radiation hazard and an internal hazard if contamination occurs; sealed sources require isotope-specific controls.
Thulium occurs naturally only as a minor constituent of rare-earth minerals, especially minerals that contain the heavy lanthanides. Weathering releases it mainly as Tm³⁺, which tends to bind to clays, oxides, phosphates, and organic matter rather than remain highly mobile. It has no known biological role. Environmental concentrations are usually very low, so ecological effects are mainly a concern near rare-earth mining, processing, or disposal sites.
Thulium is obtained as a by-product of rare-earth extraction rather than mined for its own sake. Sources include ion-adsorption clays and minerals such as monazite and xenotime that contain small fractions of heavy rare earths. Separation relies on solvent extraction, ion exchange, and conversion through oxide or salt intermediates, with cost driven more by separation complexity than by absolute crustal scarcity. Demand is small and specialized, so supply is tied to broader rare-earth processing rather than an independent commodity chain. Recycling is limited because applications use small amounts in dispersed devices or sealed sources.
Found with other rare earths in the minerals gadolinite, euxenite, xenotime, and monazite. Monazite is often 50% rare earth by weight and 0.007% thulium.
Thulium is a rare cosmic element produced mainly by neutron-capture processes in evolved stars and stellar explosions. Its odd atomic number and position among the heavy lanthanides make it much less abundant than lighter rock-forming elements and less abundant than several neighboring rare earths. In planets and meteorites it follows refractory lithophile behavior and partitions with other rare-earth elements rather than forming native metal.
- Thulium is the least abundant lanthanide that has a stable isotope.
- Natural thulium is essentially all ¹⁶⁹Tm.
- ¹⁷⁰Tm can be made by neutron irradiation of ¹⁶⁹Tm.
- Thulium was named after Thule, a classical name associated with the far north.
- Despite its rarity among lanthanides, thulium is more abundant in Earth’s crust than silver.
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
- 190 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
- 227 pm 全元素のファンデルワールス半径を比較 →
- 密度
- 9320 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.0181 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
- 1544.85 °C 全元素の融点を比較 →
- 沸点
- 1949.85 °C 全元素の沸点を比較 →
- 比熱容量
- 0.16 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 27.03 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
- 電気陰性度（Pauling）
- 1.25 全元素の電気陰性度（Pauling）を比較 →
- 電子親和力
- 1.029 eV
- 第1イオン化エネルギー
- 6.184402 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
- 12.065042 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
- 23.660081 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
- 42.410146 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
- 65.400225 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 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 4f13
熱力学的性質
- 融解熱
- 0.12437166 eV 全元素の融解熱を比較 →
- 蒸発熱
- 1.979582 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 2.404519 eV
- 原子化熱
- 2.404519 eV
- 原子化エンタルピー
- 2.406592 eV
原子核
- 陽子数
- 69 全元素の陽子数を比較 →
- 中性子数
- 100 全元素の中性子数を比較 →
- 既知の同位体
- 39 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
- Tm-169
- 発見年
- 1879
存在度
- 存在度（地殻）
- 0.52 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 1.7 × 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
- 354 pm
電子構造
- 各電子殻の電子数
- 2, 8, 18, 31, 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
- 7440-30-4 全元素のCAS登録番号を比較 →
- 項記号
- 2F°7/2
- InChI
- InChI=1S/Tm
- InChI Key
- FRNOGLGSGLTDKL-UHFFFAOYSA-N
電子配置 測定値
Tm: 4f¹³ 6s²[Xe] 4f¹³ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹³ 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 |
|---|---|---|---|
| 169 安定 | 168.9342179 ± 0.0000022 | 100.0000% | 安定 |
相／状態
理由: 融点（1544.85 °C）より1519.8 °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69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。
スペクトル線データの収録状況 ?
| イオン | 電荷 | スペクトル線の総数 | 遷移確率 | 準位の表記 |
|---|---|---|---|---|
| Tm I | 0 | 538 | 408 | 525 |
| Tm II | +1 | 267 | 13 | 13 |
| Tm III | +2 | 186 | 0 | 0 |
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Tm I | 0 | 631 |
| Tm II | +1 | 367 |
| Tm III | +2 | 128 |
| Tm IV | +3 | 8 |
| Tm V | +4 | 2 |
| Tm VI | +5 | 2 |
| Tm VII | +6 | 2 |
| Tm VIII | +7 | 2 |
| Tm IX | +8 | 2 |
| Tm X | +9 | 2 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +2 | 6 | データなし | 103 pm |
| +2 | 7 | データなし | 109.00000000000001 pm |
| +3 | 6 | データなし | 88 pm |
| +3 | 8 | データなし | 99.4 pm |
| +3 | 9 | データなし | 105.2 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 | |
|---|---|---|---|---|---|
| 169 安定 | 168.9342179 ± 0.0000022 | 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）
- 164 pm
- 共有結合半径（Pyykkö、二重結合）
- 131 pm
ファンデルワールス半径
- Alvarez
- 279 pm
- UFF
- 337.4 pm
- MM3
- 267 pm
原子半径と金属半径
- 原子半径（Rahm）
- 271 pm
番号付けの尺度
- Mendeleev
- 37
- Pettifor
- 22
- Glawe
- 20
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 6
- Robles–Bartolotti
- 5
分極率と分散
- 双極子分極率
- 144 a.u.
- 双極子分極率（不確かさ）
- 15 a.u.
- C₆ (Gould–Bučko)
- 2020 Ha·Bohr6
ミーデマパラメータ
- ミーデマモル体積
- 18.12 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 | 1818.15 K |
| 沸点 | 2223.15 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 | 1.3437 |
| 2 | p | 4.3588 |
| 2 | s | 18.0522 |
| 3 | d | 13.6257 |
| 3 | p | 20.5239 |
| 3 | s | 21.0816 |
| 4 | d | 36.056 |
| 4 | f | 40.366 |
| 4 | p | 33.012 |
| 4 | s | 31.8624 |
結晶半径の詳細 (5)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 2 | VI | 117 | ||
| 2 | VII | 123 | ||
| 3 | VI | 102 | from r^3 vs V plots, | |
| 3 | VIII | 113.4 | from r^3 vs V plots, | |
| 3 | IX | 119.2 | from r^3 vs V plots, |
同位体の崩壊形式 (58)
| 同位体 | モード | 強度 |
|---|---|---|
| 144 | p | — |
| 144 | B+ | — |
| 145 | p | 100% |
| 146 | p | 100% |
| 146 | B+ | — |
| 146 | B+p | — |
| 147 | B+ | 85% |
| 147 | p | 15% |
| 148 | B+ | 100% |
| 148 | B+p | — |
X線散乱因子 (514)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.17918 |
| 10.1617 | — | 0.18356 |
| 10.3261 | — | 0.18805 |
| 10.4931 | — | 0.19265 |
| 10.6628 | — | 0.19737 |
| 10.8353 | — | 0.2022 |
| 11.0106 | — | 0.20714 |
| 11.1886 | — | 0.21221 |
| 11.3696 | — | 0.21741 |
| 11.5535 | — | 0.22273 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
5.2×10-1 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.7×10-7 milligrams per liter
参考文献 (1)
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 Thulium.
The element property data was retrieved from publications.