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Terbium 65Tb158.924
Discovered in 1843 by C.G. Mosander at Stockholm, Sweden.
[Named after Ytterby, Sweden]
French: terbium
German: Terbium
Italian: terbio
Spanish: terbio
Description: Terbium is a
silvery metal, and a particularly rare member of the so-called rare earth
group (more correctly termed the lanthanides). It is slowly oxidised by air and
reacts with cold water. Terbium is used in solid state devices and lasers.
Materials properties
| Density: |
8829 kg/m-3 [293 K] |
| Melting point: |
1629 °K |
| Boiling point: |
3396 °K |
| Molar volume: |
19.31 cm3 |
| Thermal conductivity: |
11.1 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
7.0 x 10-6 K-1 |
| Electrical resistivity: |
114 x 10-8 [298 K] Wm |
| Mass magnetic susceptibility: |
+1.15 x 10-5(s) kg-1m3 |
| Young's modulus: |
55.7 GPa |
| Rigidity modulus: |
22.1 GPa |
| Bulk modulus: |
38.7 GPa |
| Poisson's ratio: |
0.261 GPa |
| Radii: |
Tb4+ 81; Tb3+ 97; atomic 178; covalent 159 |
| Electronegativity: |
n.a. (Pauling); 1.10 (Allred); ≤ 3.2 eV (absolute) |
| Effective nuclear charge: |
2.85 (Slater); 8.30 (Clementi); 11.39 (Froese-Fischer) |
| Number of Isotopes (incl. nuclear isomers): |
31 |
| Issotope mass range: |
145 -> 165 |
Biological data
| Biological role: |
None. |
| Toxicity |
|
| Toxic intake: |
n.a. |
| Lethal intake: |
LD 50 (chloride, oral, mouse)= > 5100 mg kg -1 |
| Hazards: |
Terbium is mildly toxic by ingestion, and is a skin and eye irritant. |
| Level in humans |
|
| Organs: |
n.a. but low |
| Daily dietary intake : |
n.a. |
| Total mass of element in average [70 kg] person: |
n.a. but very low |
Crystal data
| Crystal structure, (cell dimentions / pm), space group |
Tb orthorhombic (a=359, b=626, c=571.5), Cmcm α-Tb h.c.p. (a = 360.10, c=569.36), P63/mmc β-Tb b.c.c. (a=402), Im3m T(α -> orthorhombic) = 220 K; T(α -> β) = 1590 K |
| X-ray diffraction: mass absorption coefficients (µ/ρ)/cm2g-1 : |
CuKα 273 MoKα 67.5 |
| Neutron scattering length, b/10-12cm: |
0.738 |
| Thermal neutron capture cross-section, σa/barns : |
23.4 |
Geological data
| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Monazite* |
(Ce,La,Nd,Th,etc.)PO4 |
5.20 |
5 - 5.5 |
mon., waxy/vit. yellow-brown |
*Although not a major constituent, terbium is present in extractable amounts.
| Chief ore: |
monazite |
| World production: |
c. 10 tonnes/year |
| Main mining areas: |
USA, Brazil, India, Sri Lanka, Australia |
| Reserves: |
c. 3 x 105 tonnes |
| Specimen: |
available as chips or ingots. Safe. Terbium powders is very irritating to skin and eyes. Care! |
| Abundances |
|
| Sun: |
n.a. |
| Earth's crust: |
1.1 p.p.m. |
| Seawater: |
|
| Atlantic surface: |
1 x 10-7 p.p.m. |
| Atlantic deep: |
1.5 x 10-7 p.p.m. |
| Pacific surface: |
0.8 x 10-7 p.p.m. |
| Pacific deep: |
2.5 x 10-7 p.p.m. |
| Residence time: |
n.a. |
| Classification: |
recycled |
| Oxidation state: |
III |
Other sizes and specifications on request
© 1996 - 2008 MaTecK GmbH - Im Langenbroich 20 - D-52428 Juelich - phone: +49 (0) 2461 / 9352-0 - fax: +49 (0) 2461 / 9352-11 - Contact: info@mateck.de
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