Terbium (Tb)
lanthanideSolid
Masse atomique relative standard
158,92535 uConfiguration électronique
[Xe] 6s2 4f9Point de fusion
1355,85 °CPoint d’ébullition
3229,85 °CMasse volumique
8230 kg/m³États d’oxydation
0, +1, +2, +3, +4Électronégativité (Pauling)
N/DÉnergie d’ionisation (1re)
5,8638 eVAnnée de découverte
1843Rayon atomique
175 pmDétails
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.
Images
Propriétés
Propriétés physiques
- Rayon atomique (empirique)
- 175 pm Comparer : Rayon atomique (empirique) de tous les éléments →
- Rayon covalent
- 194 pm Comparer : Rayon covalent de tous les éléments →
- Rayon de van der Waals
- 221 pm Comparer : Rayon de van der Waals de tous les éléments →
- Masse volumique
- 8230 kg/m³ Comparer : Masse volumique de tous les éléments →
- Volume molaire
- 0,0192 L/mol
- Phase aux CNTP
- Solide Comparer : Phase aux CNTP de tous les éléments →
- Point de fusion
- 1355,85 °C Comparer : Point de fusion de tous les éléments →
- Point d’ébullition
- 3229,85 °C Comparer : Point d’ébullition de tous les éléments →
- Conductivité thermique
- 11,1 W/(m·K) Comparer : Conductivité thermique de tous les éléments →
- Capacité thermique massique
- 0,182 J/(g·K) Comparer : Capacité thermique massique de tous les éléments →
- Capacité thermique molaire
- 28,91 J/(mol·K) Comparer : Capacité thermique molaire de tous les éléments →
- Structure cristalline
- Hexagonal compact Comparer : Structure cristalline de tous les éléments →
Propriétés chimiques
- Affinité électronique
- 1,124 eV
- Énergie d’ionisation (1re)
- 5,8638 eV Comparer : Énergie d’ionisation (1re) de tous les éléments →
- Énergie d’ionisation (2e)
- 11,51304 eV Comparer : Énergie d’ionisation (2e) de tous les éléments →
- Énergie d’ionisation (3e)
- 21,820075 eV Comparer : Énergie d’ionisation (3e) de tous les éléments →
- Énergie d’ionisation (4e)
- 39,330135 eV Comparer : Énergie d’ionisation (4e) de tous les éléments →
- Énergie d’ionisation (5e)
- 66,500229 eV Comparer : Énergie d’ionisation (5e) de tous les éléments →
- États d’oxydation
- 0, +1, +2, +3, +4 Comparer : États d’oxydation de tous les éléments →
- Électrons de valence
- 3 Comparer : Électrons de valence de tous les éléments →
- Configuration électronique
- [Xe] 6s2 4f9
Propriétés thermodynamiques
- Enthalpie de fusion
- 0,1119345 eV Comparer : Enthalpie de fusion de tous les éléments →
- Enthalpie de vaporisation
- 3,016013 eV Comparer : Enthalpie de vaporisation de tous les éléments →
- Enthalpie de sublimation
- 4,031715 eV
- Enthalpie d’atomisation
- 4,031715 eV
- Enthalpie d’atomisation
- 4,028605 eV
Propriétés nucléaires
- Protons
- 65 Comparer : Protons de tous les éléments →
- Neutrons
- 94 Comparer : Neutrons de tous les éléments →
- Isotopes connus
- 40 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 1 Comparer : Isotopes stables de tous les éléments →
- Isotope le plus stable
- Tb-159
- Année de découverte
- 1843
Abondance
- Abondance (croûte terrestre)
- 1,2 mg/kg Comparer : Abondance (croûte terrestre) de tous les éléments →
- Abondance (océan)
- 1,4 × 10−7 mg/L Comparer : Abondance (océan) de tous les éléments →
Structure cristalline
- Paramètre de maille a
- 360 pm
Structure électronique
- Électrons par couche
- 2, 8, 18, 27, 8, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 7440-27-9 Comparer : Numéro CAS de tous les éléments →
- Symbole de terme
- 6H°15/2
- InChI
- InChI=1S/Tb
- Clé InChI
- GZCRRIHWUXGPOV-UHFFFAOYSA-N
Configuration électronique Mesuré
Tb: 4f⁹ 6s²[Xe] 4f⁹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁹ 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 |
|---|---|---|---|
| 159 Stable | 158,9253547 ± 0,0000019 | 100,0000% | Stable |
Phase / État
Explication: 1330,8 °C en dessous du point de fusion (1355,85 °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 65. Tri par charge ionique croissante.
Raies répertoriées ?
| Ion | Charge | Nombre total de raies | Probabilités de transition | Désignations des niveaux |
|---|---|---|---|---|
| Tb I | 0 | 248 | 0 | 10 |
| Tb II | +1 | 424 | 8 | 18 |
| Tb IV | +3 | 48 | 0 | 0 |
Niveaux répertoriés ?
| Ion | Charge | Niveaux |
|---|---|---|
| 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 |
Rayons ioniques
| Charge | Coordinence | Spin | Rayon |
|---|---|---|---|
| +3 | 6 | N/D | 92.30000000000001 pm |
| +3 | 7 | N/D | 98 pm |
| +3 | 8 | N/D | 104 pm |
| +3 | 9 | N/D | 109.5 pm |
| +4 | 6 | N/D | 76 pm |
| +4 | 8 | N/D | 88 pm |
Composés
Isotopes (1)
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie | Mode de désintégration | |
|---|---|---|---|---|---|
| 159 Stable | 158,9253547 ± 0,0000019 | 100,0000% | Stable | stable |
Propriétés étendues
Rayons covalents (données étendues)
- Rayon covalent (Pyykkö)
- 168 pm
- Rayon covalent (Pyykkö, liaison double)
- 135 pm
Rayons de van der Waals
- Alvarez
- 279 pm
- UFF
- 345,1 pm
- MM3
- 270 pm
Rayons atomiques et métalliques
- Rayon atomique (Rahm)
- 276 pm
Échelles de numérotation
- Mendeleev
- 29
- Pettifor
- 26
- Glawe
- 25
Échelles d’électronégativité
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 3
Polarisabilité et dispersion
- Polarisabilité dipolaire
- 170 a.u.
- Polarisabilité dipolaire (incertitude)
- 20 a.u.
- C₆ (Gould–Bučko)
- 2590 Ha·Bohr6
Paramètres de Miedema
- Volume molaire de Miedema
- 19,32 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 | 1632,15 K |
| Point d’ébullition | 3503,15 K |
Catégories d’états d’oxydation
Données de référence avancées
Constantes d’écran (13)
| n | Orbitale | 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 |
Détail des rayons cristallins (6)
| Charge | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 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 |
Modes de désintégration des isotopes (63)
| Isotope | Mode | Intensité |
|---|---|---|
| 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% |
Facteurs de diffusion des rayons X (514)
| Énergie (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 |
Données complémentaires
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.2 milligrams per kilogram
Références (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.4×10-7 milligrams per liter
Références (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.
Références (1)
- [6] Terbium https://periodic.lanl.gov/65.shtml
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 Terbium.
The element property data was retrieved from publications.