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Europium 63Eu151.96
Discovered in 1901 by E.A. Demarcay
at Paris, France.
[Named after Europe]
French: europium
German: Europium
Italian: europio
Spanish: europio
Description: Europium
is a soft, silvery metal which is one of the rarest of the
so-called rare earth group (more correctly thermed the landthanides). It is the most reactive
of these metals, reacting quickly with oxygen and
water. It is little used, but some is employed in thin-film superconductor alloys.
Materials properties
| Density: |
5243 kg/m-3 [293 K] |
| Melting point: |
1095 °K |
| Boiling point: |
1870 °K |
| Molar volume: |
28.98 cm3 |
| Thermal conductivity: |
13.9 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
32 x 10-6 K-1 |
| Electrical resistivity: |
990.0 x 10-8 [298 K] Wm |
| 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 |
| Radii: |
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 |
| Issotope mass range: |
141 -> 160 |
Biological data
| Biological role: |
None. |
| 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 |
|
| Organs: |
n.a. but very 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 |
b.c.c. (a=485.20), Im3m |
| X-ray diffraction: mass absorption coefficients (µ/ρ)/cm2g-1: |
CuKα 425 MoKα 61.5 |
| Neutron scattering length, b/10-12cm: |
0.722 |
| Thermal neutron capture cross-section, σa/barns: |
4600 |
Geological data
| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Bastnäsite* |
(Ce,La,etc.)CO3F |
4.9 |
4 - 4.5 |
hex. vit./gresy yellow |
| Monazite* |
(Ce,La,Nd,Th,etc.)PO4 |
5.2 |
5 - 5.5 |
mon. waxy/vit. yellow-brown |
*Although not a major constituent, europium is present in extractable amounts.
| Chief ore: |
monazite, bastnäsite |
| 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. Safe. |
| Abundances |
|
| Sun: |
5 (relative to H = 1 x 1023) |
| Earth's crust: |
2.1 p.p.m. |
| Seawater: |
|
| Atlantic surface: |
0.9 x 10-7 p.p.m. |
| Atlantic deep: |
1.5 x 10-7 p.p.m. |
| Pacific surface: |
1.0 x 10-7 p.p.m. |
| Pacific deep: |
2.7 x 10-7 p.p.m. |
| Residence time: |
500 years |
| Classification: |
recycled |
| Oxidation state: |
III |
Other sizes and specifications on request
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