Thulium (Tm)
lanthanideSolid
Masse atomique relative standard
168,93422 uConfiguration électronique
[Xe] 6s2 4f13Point de fusion
1544,85 °CPoint d’ébullition
1949,85 °CMasse volumique
9320 kg/m³États d’oxydation
0, +1, +2, +3Électronégativité (Pauling)
1,25Énergie d’ionisation (1re)
6,184402 eVAnnée de découverte
1879Rayon atomique
175 pmDétails
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.
Images
Propriétés
Propriétés physiques
- Rayon atomique (empirique)
- 175 pm Comparer : Rayon atomique (empirique) de tous les éléments →
- Rayon covalent
- 190 pm Comparer : Rayon covalent de tous les éléments →
- Rayon de van der Waals
- 227 pm Comparer : Rayon de van der Waals de tous les éléments →
- Masse volumique
- 9320 kg/m³ Comparer : Masse volumique de tous les éléments →
- Volume molaire
- 0,0181 L/mol
- Phase aux CNTP
- Solide Comparer : Phase aux CNTP de tous les éléments →
- Point de fusion
- 1544,85 °C Comparer : Point de fusion de tous les éléments →
- Point d’ébullition
- 1949,85 °C Comparer : Point d’ébullition de tous les éléments →
- Capacité thermique massique
- 0,16 J/(g·K) Comparer : Capacité thermique massique de tous les éléments →
- Capacité thermique molaire
- 27,03 J/(mol·K) Comparer : Capacité thermique molaire de tous les éléments →
- Structure cristalline
- Hexagonal compact Comparer : Structure cristalline de tous les éléments →
Propriétés chimiques
- Électronégativité (Pauling)
- 1,25 Comparer : Électronégativité (Pauling) de tous les éléments →
- Affinité électronique
- 1,029 eV
- Énergie d’ionisation (1re)
- 6,184402 eV Comparer : Énergie d’ionisation (1re) de tous les éléments →
- Énergie d’ionisation (2e)
- 12,065042 eV Comparer : Énergie d’ionisation (2e) de tous les éléments →
- Énergie d’ionisation (3e)
- 23,660081 eV Comparer : Énergie d’ionisation (3e) de tous les éléments →
- Énergie d’ionisation (4e)
- 42,410146 eV Comparer : Énergie d’ionisation (4e) de tous les éléments →
- Énergie d’ionisation (5e)
- 65,400225 eV Comparer : Énergie d’ionisation (5e) de tous les éléments →
- États d’oxydation
- 0, +1, +2, +3 Comparer : États d’oxydation de tous les éléments →
- Électrons de valence
- 3 Comparer : Électrons de valence de tous les éléments →
- Configuration électronique
- [Xe] 6s2 4f13
Propriétés thermodynamiques
- Enthalpie de fusion
- 0,12437166 eV Comparer : Enthalpie de fusion de tous les éléments →
- Enthalpie de vaporisation
- 1,979582 eV Comparer : Enthalpie de vaporisation de tous les éléments →
- Enthalpie de sublimation
- 2,404519 eV
- Enthalpie d’atomisation
- 2,404519 eV
- Enthalpie d’atomisation
- 2,406592 eV
Propriétés nucléaires
- Protons
- 69 Comparer : Protons de tous les éléments →
- Neutrons
- 100 Comparer : Neutrons de tous les éléments →
- Isotopes connus
- 39 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 1 Comparer : Isotopes stables de tous les éléments →
- Isotope le plus stable
- Tm-169
- Année de découverte
- 1879
Abondance
- Abondance (croûte terrestre)
- 0,52 mg/kg Comparer : Abondance (croûte terrestre) de tous les éléments →
- Abondance (océan)
- 1,7 × 10−7 mg/L Comparer : Abondance (océan) de tous les éléments →
Structure cristalline
- Paramètre de maille a
- 354 pm
Structure électronique
- Électrons par couche
- 2, 8, 18, 31, 8, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 7440-30-4 Comparer : Numéro CAS de tous les éléments →
- Symbole de terme
- 2F°7/2
- InChI
- InChI=1S/Tm
- Clé InChI
- FRNOGLGSGLTDKL-UHFFFAOYSA-N
Configuration électronique Mesuré
Tm: 4f¹³ 6s²[Xe] 4f¹³ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹³ 6s²Modèle atomique
Les isotopes diffèrent par leur nombre de neutrons, leur masse et leur stabilité — pas par la configuration électronique de l’atome neutre.
Modèle atomique schématique, non à l’échelle.
Empreinte atomique
Spectre d’émission / d’absorption
Distribution isotopique
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie |
|---|---|---|---|
| 169 Stable | 168,9342179 ± 0,0000022 | 100,0000% | Stable |
Phase / État
Explication: 1519,8 °C en dessous du point de fusion (1544,85 °C)
Schématique, non à l’échelle
Points de transition de phase
Énergies de transition
Énergie nécessaire pour faire fondre 1 mol au point de fusion
Énergie nécessaire pour vaporiser 1 mol au point d’ébullition
Énergie nécessaire pour sublimer 1 mol au point de sublimation
Masse volumique
Dans les conditions standard
Dans les conditions standard
Spectres atomiques
Affichage de 10 sur 69. Tri par charge ionique croissante.
Raies répertoriées ?
| Ion | Charge | Nombre total de raies | Probabilités de transition | Désignations des niveaux |
|---|---|---|---|---|
| Tm I | 0 | 538 | 408 | 525 |
| Tm II | +1 | 267 | 13 | 13 |
| Tm III | +2 | 186 | 0 | 0 |
Niveaux répertoriés ?
| Ion | Charge | Niveaux |
|---|---|---|
| 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 |
Rayons ioniques
| Charge | Coordinence | Spin | Rayon |
|---|---|---|---|
| +2 | 6 | N/D | 103 pm |
| +2 | 7 | N/D | 109.00000000000001 pm |
| +3 | 6 | N/D | 88 pm |
| +3 | 8 | N/D | 99.4 pm |
| +3 | 9 | N/D | 105.2 pm |
Composés
Isotopes (1)
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie | Mode de désintégration | |
|---|---|---|---|---|---|
| 169 Stable | 168,9342179 ± 0,0000022 | 100,0000% | Stable | stable |
Propriétés étendues
Rayons covalents (données étendues)
- Rayon covalent (Pyykkö)
- 164 pm
- Rayon covalent (Pyykkö, liaison double)
- 131 pm
Rayons de van der Waals
- Alvarez
- 279 pm
- UFF
- 337,4 pm
- MM3
- 267 pm
Rayons atomiques et métalliques
- Rayon atomique (Rahm)
- 271 pm
Échelles de numérotation
- Mendeleev
- 37
- Pettifor
- 22
- Glawe
- 20
Échelles d’électronégativité
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 6
- Robles–Bartolotti
- 5
Polarisabilité et dispersion
- Polarisabilité dipolaire
- 144 a.u.
- Polarisabilité dipolaire (incertitude)
- 15 a.u.
- C₆ (Gould–Bučko)
- 2020 Ha·Bohr6
Paramètres de Miedema
- Volume molaire de Miedema
- 18,12 cm3/mol
- Densité électronique de Miedema
- 2
Risque d’approvisionnement et économie
- Concentration de la production
- 97
- Risque relatif d’approvisionnement
- 10
- Répartition des réserves
- 50
- Stabilité politique (principal producteur)
- 24
- Stabilité politique (principal détenteur de réserves)
- 24
Transitions de phase et allotropes
| Point de fusion | 1818,15 K |
| Point d’ébullition | 2223,15 K |
Catégories d’états d’oxydation
Données de référence avancées
Constantes d’écran (13)
| n | Orbitale | 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 |
Détail des rayons cristallins (5)
| Charge | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 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, |
Modes de désintégration des isotopes (58)
| Isotope | Mode | Intensité |
|---|---|---|
| 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 | — |
Facteurs de diffusion des rayons X (514)
| Énergie (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 |
Données complémentaires
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
5.2×10-1 milligrams per kilogram
Références (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.7×10-7 milligrams per liter
Références (1)
Références
(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.