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About Terbium

Terbium Bohr

In 1787, army-lieutenant and chemist Carl Axel Arrhenius found a rock in a quarry near the Swedish village of Ytterby which he suspected contained the newly discovered element tungsten. Analysis by other chemists did not bear out his suspicions, but ultimately four new elements were identified from Arrhenius’s ytterbite. Carl Gustaf Mosander isolated three new oxides in 1843, one of which he named terbia, giving the corresponding element the name terbium.

A variety of terbium-doped compounds can act as phosphors for use in television screens, other displays, lighting, or sensors. Most notably, terbium green phosphors are used in trichromatic fluorescent lamps along with europium blue and red phosphors to produce white light with greater energy efficiency than incandescent lighting. In zirconia oxide ceramics, terbium can act both as a light-emitting dopant and a crystal stabilizer, producing a material with excellent structural and optical properties. Other terbium doped compounds have useful electrical properties that make them potentially useful in the semiconductor industry.

Terfenol-D is an alloy of terbium, iron, and dysprosium that is magnetostrictive: it contracts or expands when exposed to magnetic fields. This property allows direct conversion between electrical and mechanical power, and the alloy is used in sensors, actuators, and acoustic and ultrasonic transducers, and active noise and vibration cancelling devices. Terbium was also a component of gadolinium-terbium-iron thin films used in magneto-optical memory storage devices and specialized compact discs (CD-MO), but other forms of computer memory are currently preferred for most applications. Additionally, engineered terbium-binding peptides are being developed for use as sensitive optical biosensors for sensing enzymatic activity, and several radioactive terbium isotopes are being developed for medical applications as diagnostic tracers or cancer treatments.

Terbium is a rare earth element and can be found in any rare earth containing mineral, but as a heavy rare earth element (HREE) it is more common in HREE-enriched minerals such as xenotime and euxenite. Additionally, terbium is present in ion adsorption clays, which are a major source of HREEs due to their relative ease of processing, despite the low percentage quantities of rare earths they contain.

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Elemental Terbium Terbium is primarily used in phosphors, particularly in fluorescent lamps and as the high intensity green emitter used in projection televisions, such as the yttrium-aluminum-garnet (Tb:YAG) variety. Terbium alloys are also used in magneto-optic recording films, such as Tb-Fe-Co. Terbium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. High Purity (99.999%) Terbium (Tb) Sputtering TargetTerbium nanoparticles and nanopowders provide ultra-high surface area which nanotechnology High Purity (99.999%) Terbium Oxide (Tb4O7) Powderresearch and recent experiments demonstrate function to create new and unique properties and benefits. Terbium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Terbium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Terbium Properties

Terbium Bohr ModelTerbium (Tb) atomic and molecular weight, atomic number and elemental symbolTerbium is a Block F, Group 3, Period 6 element. The number of electrons in each of Terbium's shells is 2, 8, 18, 27, 8, 2 and its electronic configuration is [Xe]4f9 6s2. The terbium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-27-9, terbium has a silvery-white appearance. Terbium was discovered and first isolated by Carl Gustaf Mosander in 1842. It is named after "Ytterby", the town in Sweden where it was discovered.

Symbol: Tb
Atomic Number: 65
Atomic Weight: 158.93
Element Category: Lanthanide
Group, Period, Block: n/a, 6, f
Color: silvery-gray/ silvery white
Other Names: Terbio, Térbio
Melting Point: 1356°C, 2472.8°F, 1629.15 K 
Boiling Point: 3230°C, 5846°F, 3503.15 K
Density: 8219 kg/m3
Liquid Density @ Melting Point: 7.65 g·cm3
Density @ 20°C: 8.27 g/cm3
Density of Solid: 8219 kg·m3
Specific Heat: 0.0437 Cal/g/K @ 25 °C
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 16.3
Heat of Vaporization (kJ·mol-1): 391
Heat of Atomization (kJ·mol-1): 390.62
Thermal Conductivity: 0.111 W/cm/K @ 298.2 K
Thermal Expansion: (r.t.) (poly) 10.3 µm/(m·K)
Electrical Resistivity: (r.t.) (poly) 1.150 nΩ·m
Tensile Strength: 60 MPa
Molar Heat Capacity: 28.91 J·mol-1·K-1
Young's Modulus: ( form) 55.7 GPa
Shear Modulus: ( form) 22.1 GPa
Bulk Modulus: ( form) 38.7 GPa
Poisson Ratio: ( form) 0.261
Mohs Hardness: N/A
Vickers Hardness: 863 MPa
Brinell Hardness: 677 MPa
Speed of Sound: (20 °C) 2620 m·s-1
Pauling Electronegativity: N/A
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.1
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: N/A
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 65
Protons: 65
Neutrons: 94
Electron Configuration: [Xe]4f9 6s2
Atomic Radius: 177 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 194±5 pm
Covalent Radius (Å): 1.81
Van der Waals Radius: 221 pm
Oxidation States: 4, 3, 2, 1 (weakly basic oxide)
Phase: Solid
Crystal Structure: hexagonal close-packed
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 565.77 kJ·mol-1
2nd Ionization Energy: 1111.52 kJ·mol-1
3rd Ionization Energy: 2114.01 kJ·mol-1
CAS Number: 7440-27-9
EC Number: 231-137-6
MDL Number: MFCD00011256
Beilstein Number: N/A
SMILES Identifier: [Tb]
InChI Identifier: InChI=1S/Tb
PubChem CID: 23958
ChemSpider ID: 22397
Earth - Total: 54 ppb
Mercury - Total: 41 ppb
Venus - Total: 56 ppb 
Earth - Seawater (Oceans), ppb by weight: 0.00014
Earth - Seawater (Oceans), ppb by atoms: 0.000005
Earth -  Crust (Crustal Rocks), ppb by weight: 940
Earth -  Crust (Crustal Rocks), ppb by atoms: 120
Sun - Total, ppb by weight: 0.1
Sun - Total, ppb by atoms: 0.001
Stream, ppb by weight: 0.008
Stream, ppb by atoms: 0.0001
Meterorite (Carbonaceous), ppb by weight: 40
Meterorite (Carbonaceous), ppb by atoms: 5
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: Carl Gustaf Mosander
Discovery Date: 1842
First Isolation: N/A

Health, Safety & Transportation Information for Terbium

Terbium is considered to be somewhat toxic. Safety data for Terbium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Terbium.

Safety Data
Material Safety Data Sheet MSDS
Signal Word Danger
Hazard Statements H228
Hazard Codes F
Risk Codes 11
Safety Precautions N/A
RTECS Number N/A
Transport Information N/A
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)

Terbium Isotopes

Naturally occurring terbium (Tb) has one stable isotope: 159Tb

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
135Tb 135 0.94(+33-22) ms Unknown (7/2-) N/A N/A -
136Tb 135.96138(64)# 0.2# s Unknown N/A N/A 1063.04 -
137Tb 136.95598(64)# 600# ms Unknown 11/2-# N/A 1080.43 -
138Tb 137.95316(43)# 800# ms [>200 ns] β+ to 138Gd; p to 137Gd N/A N/A 1088.51 -
139Tb 138.94829(32)# 1.6(2) s β+ to 139Gd; β+ + p to 139Eu 11/2-# N/A 1105.9 -
140Tb 139.94581(86) 2.4(2) s β+ to 140Gd 5 N/A 1113.98 -
141Tb 140.94145(11) 3.5(2) s β+ to 141Gd (5/2-) N/A 1122.06 -
142Tb 141.93874(32)# 597(17) ms β+ to 142Gd; β+ + p to 141Eu 1+ N/A 1139.46 -
143Tb 142.93512(6) 12(1) s β+ to 143Gd (11/2-) N/A 1147.54 -
144Tb 143.93305(3) ~1 s β+ to 144Gd 1+ N/A 1155.61 -
145Tb 144.92927(6) 20# min β+ to 145Gd (3/2+) N/A 1173.01 -
146Tb 145.92725(5) 8(4) s β+ to 146Gd 1+ N/A 1181.09 -
147Tb 146.924045(13) 1.64(3) h β+ to 147Gd 1/2+# N/A 1189.17 -
148Tb 147.924272(15) 60(1) min β+ to 148Gd 2- N/A 1197.25 -
149Tb 148.923246(5) 4.118(25) h β+ to 149Gd; α to 145Eu 1/2+ N/A 1205.32 -
150Tb 149.923660(8) 3.48(16) h β+ to 150Gd; α to 146Eu (2-) N/A 1213.4 -
151Tb 150.923103(5) 17.609(1) h β+ to 151Gd; α to 147Eu 1/2(+) N/A 1221.48 -
152Tb 151.92407(4) 17.5(1) h β+ to 152Gd; α to 148Eu 2- N/A 1229.56 -
153Tb 152.923435(5) 2.34(1) d EC to 153Gd 5/2+ 3.5 1237.64 -
154Tb 153.92468(5) 21.5(4) h EC to 154Gd; β- to 154Dy 0(+#) 0.9 1245.72 -
155Tb 154.923505(13) 5.32(6) d EC to 155Gd 3/2+ 2 1253.8 -
156Tb 155.924747(5) 5.35(10) d EC to 156Gd; β- to 156Dy 3- 1.4 1261.87 -
157Tb 156.9240246(27) 71(7) y EC to 157Gd 3/2+ 2 1269.95 -
158Tb 157.9254131(28) 180(11) y EC to 158Gd; β- to 158Dy 3- 1.76 1278.03 -
159Tb 158.9253468(27) STABLE - 3/2+ 2.014 1286.11 100
160Tb 159.9271676(27) 72.3(2) d β- to 160Dy 3- 1.79 1294.19 -
161Tb 160.9275699(28) 6.906(19) d β- to 161Dy 3/2+ 2.2 1302.27 -
162Tb 161.92949(4) 7.60(15) min β- to 162Dy 1- N/A 1310.35 -
163Tb 162.930648(5) 19.5(3) min β- to 163Dy 3/2+ N/A 1309.11 -
164Tb 163.93335(11) 3.0(1) min β- to 164Dy (5+) N/A 1317.19 -
165Tb 164.93488(21)# 2.11(10) min β- to 165Dy 3/2+# N/A 1325.27 -
166Tb 165.93799(11) 25.6(22) s β- to 166Dy N/A N/A 1333.35 -
167Tb 166.94005(43)# 19.4(27) s β- to 167Dy 3/2+# N/A 1332.11 -
168Tb 167.94364(54)# 8.2(13) s β- to 168Dy 4-# N/A 1340.19 -
169Tb 168.94622(64)# 2# s β- to 169Dy 3/2+# N/A 1348.27 -
170Tb 169.95025(75)# 3# s β- to 170Dy N/A N/A 1347.03 -
171Tb 170.95330(86)# 500# ms β- to 171Dy 3/2+# N/A 1355.11 -
Terbium Elemental Symbol

Recent Research & Development for Terbium

  • Effects of Terbium (III) on Signaling Molecules in Horseradish. Wang L, Zhang X, Zhou Q, Huang X. Biol Trace Elem Res. 2015 Mar
  • Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt. Robaschik P, Siles PF, Bülz D, Richter P, Monecke M, Fronk M, Klyatskaya S, Grimm D, Schmidt OG, Ruben M, Zahn DR, Salvan G. Beilstein J Nanotechnol. 2014 Nov 11
  • Terbium doped SnO2 nanoparticles as white emitters and SnO2:5Tb/Fe3O4 magnetic luminescent nanohybrids for hyperthermia application and biocompatibility with HeLa cancer cells. Singh LP, Singh NP, Srivastava SK. Dalton Trans. 2015 Mar 9.
  • Synthesis, crystal structure, and properties of a 1-D terbium-substituted monolacunary Keggin-type polyoxotungstate. Ma P, Si Y, Wan R, Zhang S, Wang J, Niu J. Spectrochim Acta A Mol Biomol Spectrosc. 2015 Mar 5
  • Detecting free hemoglobin in blood plasma and serum with luminescent terbium complexes. Morgner F, Lecointre A, Charbonnière LJ, Löhmannsröben HG. Phys Chem Chem Phys. 2015 Jan 21
  • Terbium-based time-gated Förster resonance energy transfer imaging for evaluating protein-protein interactions on cell membranes. Lindén S, Singh MK, Wegner KD, Regairaz M, Dautry F, Treussart F, Hildebrandt N. Dalton Trans. 2015 Mar 3
  • A ratiometric fluorescent nanoprobe based on terbium functionalized carbon dots for highly sensitive detection of an anthrax biomarker. Chen H, Xie Y, Kirillov AM, Liu L, Yu M, Liu W, Tang Y. Chem Commun (Camb). 2015 Mar 10
  • Monoxides of small terbium clusters: a density functional theory investigation. Zhang GL, Yuan HK, Chen H, Kuang AL, Li Y, Wang JZ, Chen J. J Chem Phys. 2014 Dec 28
  • A Terbium(III)-Complex-Based On-Off Fluorescent Chemosensor for Phosphate Anions in Aqueous Solution and Its Application in Molecular Logic Gates. Wang YW, Liu SB, Yang YL, Wang PZ, Zhang AJ, Peng Y. ACS Appl Mater Interfaces. 2015 Feb 25
  • Effective photosensitized energy transfer of nonanuclear terbium clusters using methyl salicylate derivatives. Omagari S, Nakanishi T, Seki T, Kitagawa Y, Takahata Y, Fushimi K, Ito H, Hasegawa Y. J Phys Chem A. 2015 Mar 12
  • Click-conjugation of binuclear terbium(III) complex for real-time detection of tyrosine phosphorylation. Akiba H, Sumaoka J, Tsumoto K, Komiyama M. Anal Chem. 2015 Mar 11.
  • Fabrication and characterization of cerium-doped terbium gallium garnet with high magneto-optical properties. Chen Z, Hang Y, Yang L, Wang J, Wang X, Hong J, Zhang P, Shi C, Wang Y. Opt Lett. 2015 Mar 1
  • Synthesis, crystal structure and fluorescence properties of terbium complexes with phenoxyacetic acid and 2,4,6-tris-(2-pyridyl)-s-triazine. Wang ZX, Wang AL, Wei XY, Qu YR, Yue B, Kang J, Chu HB, Zhao YL. Luminescence. 2015 Jan 13.
  • KINATEST-ID: A Pipeline To Develop Phosphorylation-Dependent Terbium Sensitizing Kinase Assays. Lipchik AM, Perez M, Bolton S, Dumrongprechachan V, Ouellette SB, Cui W, Parker LL. J Am Chem Soc. 2015 Feb 25
  • Crystal structure of an eight-coordinate terbium(III) ion chelated by N,N'-bis-(2-hy-droxy-benz-yl)-N,N'-bis-(pyridin-2-ylmeth-yl)ethyl-enedi-amine (bbpen(2-)) and nitrate. Gregório T, Rüdiger AL, Nunes GG, Soares JF, Hughes DL. Acta Crystallogr E Crystallogr Commun. 2015 Jan 1
  • Preparation, characterization, and properties of PMMA-doped polymer film materials: a study on the effect of terbium ions on luminescence and lifetime enhancement. Zhang HJ, Fan RQ, Wang XM, Wang P, Wang YL, Yang YL. Dalton Trans. 2015 Jan 28
  • The synthesis, crystal structure and magnetic properties of a one-dimensional terbium(III)-octacyanidomolybdate(V) assembly. Shen H. Acta Crystallogr C Struct Chem. 2014 Dec
  • Syntheses and luminescent properties of a copolymer of terbium-p-aminobenzoic acid-methacrylic acid and styrene. Zhang AQ, Yang YM, Li LP, Zhai GM, Jia HS, Liu XG, Xu BS. Luminescence. 2015 Feb 24.
  • Magnetofluorescent micellar complexes of terbium(III) as potential bimodal contrast agents for magnetic resonance and optical imaging. Harris M, Carron S, Vander Elst L, Laurent S, Muller RN, Parac-Vogt TN. Chem Commun (Camb). 2015 Feb 18
  • Toxic effects of heavy metal terbium ion on the composition and functions of cell membrane in horseradish roots. Yang Q, Wang L, Zhou Q, Huang X. Ecotoxicol Environ Saf. 2015 Jan