Wir sind führender Hersteller und Lieferant von Forschungsmaterialien
1901 von E.-A. Demarcay in Paris, Frankreich, entdeck.
[Nach Europa bennant]
French: europium
English: europium
Italian: europio
Spanish: europio
Beschreibung: Das seltenste und reaktivste Lanthanoid. Weiches, silberfarbiges Metall, das schnell mit Sauerstoff und Wasser reagiert. Wenig verwendet, z. B. für dünne Schichten supraleitender Legierungen.
Crystal structure: |
(cell dimensions/pm), space group, |
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X-ray diffractions mass absorption coefficients: | CuKa 425 (µ/r) / cm2g-1 MoKa 61.5 (µ/r) / cm2g-1 |
Neutron scattering length: | 0.722 b/10-12 cm |
Thermal neutron capture cross-section: | 4600 sa / barns |
Density: | 5243 kg/m-3 [293 K] |
Melting point: | 821,85°C / 1095°K |
Boiling point: | 1596,85°C / 1870°K |
Molar volume: | 28.98 cm3 |
Thermal conductivity: | 13.9 [300 K] W m-1K-1 |
Coefficient of linear thermal expansion: | 32 x 10-6 K-1 |
Electrical resistivity: | 990.0 x 10-8 [298 K] Ωm |
Mass magnetic susceptibility: | +2.81 x 10-6(s) kg-1m3 |
Young's modulus: | 18.2 GPa |
Rigidity modulus: | 7.9 GPa |
Bulk modulus: | 8.3 GPa |
Poisson's ratio: | 0.152 GPa |
Radi: | Eu3+ 98;Eu2+ 112; atomic 204; covalent 185 |
Electronegativity: | n.a. (Pauling); 1.01 (Allred); ≤3.1 eV (absolute) |
Effective nuclear charge: | 2.85 (Slater); 8.11 (Clementi); 11.17 (Froese-Fischer) |
Number of Isotopes (incl. nuclear isomers): | 26 |
Isotope mass range: | 141 -> 160 |
Biological role: | None. |
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Toxicity | |
Toxic intake: | n.a. |
Lethal intake: | LD50 (nitrate, oral, mouse) > 5000 mg Kg-1 |
Hazards: | Europium is mildly toxic by ingestion. |
Level in humans | n.a. but very low |
Blood: | n.a. |
Bone: | n.a. |
Liver: | n.a. |
Muscle: | n.a. |
Daily dietary intake: | n.a. |
Total mass of element in average [70 kg] person: |
n.a. but very low |
Minerals: | ||||
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Mineral | Formula | Density | Hardness | Crystal apperance |
Bastnäsite-Ce* | (Ce, La, etc.) CO3F | 4.9 | 4 - 4.5 | hex., vit/ greasy yellow |
Monazite-Ce* | (Ce, La, Nd, Th, etc.)PO4 | 5.20 | 5 - 5.5 | mon., waxy/ vit. yellow-brown |
* Although not a major constituent, europium is present in extractable amounts.
Chief ores: | monazite, bastnäsite |
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World production: | c. 400 tonnes/year |
Main mining areas: | USA, Brazil, India, Sri Lanka, Australia, China |
Reserves: | c. 1.5 x 106 tonnes |
Specimen: | available as ingots. Safer. |
Abundances | |
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Sun: | 5 (relative to H = 1 x 1012) |
Earth's crust: | 2.1 ppm |
Seawater | |
Altantic surface: | 0.9 x 10-7 ppm |
Atlantic deep: | 1.5 x 10-7 ppm |
Pacific surface: | 1.0 x 10-7 ppm |
Pacific deep: | 2.7 x 10-7 ppm |
Residence time: | 500 years |
Classification: | recycled |
Oxidation state: | III |
Source: Emsley, J. (1998) The Elements (3rd Edition)
Other sizes and specifications on request