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Cobalt single crystal 27Co58.933
Discovered in 1735 by Georg Brandt at Stockholm, Sweden.
[German: kobald = goblin]
French: cobalt
German: kobalt
Italian: cobalto
Spanish: cobalto
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Description: Cobalt is a lustrous, silvery-blue, hard metal which is also ferromagnetic.
It is stable in air, unaffected by water, but slowly attacked by dilute acids. 60Co is a useful radioisotope. Cobalt is used in alloys for magnets, in ceramics, in catalysts and in paints.
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Metal single crystal properties
| State: |
single crystal |
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| Crystal structure: |
hexagonal |
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| Production method: |
Czochralski |
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| Standard size: |
diameter 8-10mm
thickness 1-2mm |
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| Orientation: |
(0001), (1-100) and (11-20) |
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| Orientation accuracy: |
<2°, <1°, <0.5° or <0.1° |
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| Polishing: |
as cut, one or two sides polished |
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| Roughness of surface: |
<0.03µm |
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| Purity: |
99.99% |
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| Typical analysis (ppm): |
Ag 0.3
Al 0.42
As 2.2
C 5.5
Ca 0.08
Cl 0.27
Cu 0.46
Cr 5.9
Fe 17
Mg 0.76 |
Mn 0.07
Mo < 0.1
N 0.24
Na 0.44
Ni 22
O 11.0
S 1.3
Si 2.9
Ti 1.1
Zn 0.2
Co balance |
Further Materials properties
| Crystal structure: |
(cell dimensions/pm), space group,
a-Co f.c.c. (a=354.41), Fm3m
e-Co h.c.p. (a=250.7, c=406.9), P63/mmc
(a -> e)=690 K |
| X-ray diffractions mass absorption coefficients: |
CuKa 313 (µ/r) / cm2g-1
MoKa 42.5 (µ/r) / cm2g-1
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| Neutron scattering length: |
0.278 b/10-12 cm |
| Thermal neutron capture cross-section: |
37.2 sa / barns
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| Density: |
8.9 g/cm3 |
| Melting point: |
1494.85 °C / 1768 °K |
| Boiling point: |
2869.85 °C / 3143 °K |
| Molar volume: |
6.62 cm3 |
| Thermal conductivity: |
100 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
13.36 x 10-6 K-1 |
| Electrical resistivity: |
6.24x10-8 [293 K] Wm |
| Mass magnetic susceptibility: |
ferromagnetic |
| Young's modulus: |
211 GPa |
| Rigidity modulus: |
82 GPa |
| Bulk modulus: |
181.5 GPa |
| Poisson's ratio: |
0.32 GPa |
| Radii: |
Co3+ 57; Co2+ 82; atomic 125; covalent 116 |
| Electronegativity: |
1.88 (Pauling); 1.70 (Allred); 4.3 eV (absolute) |
| Effective nuclear charge: |
3.90 (Slater); 5.58 (Clementi); 7.63 (Froese-Fischer) |
| Number of Isotopes (incl. nuclear isomers): |
17 |
| Issotope mass range: |
35 -> 64 |
Biological data
| Biological role: |
Essential to most species, including humans. |
| Toxicity |
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| Toxic intake: |
500 mg |
| Lethal intake: |
LD50 (chloride, oral, rat) = 80 mg kg-1 |
| Hazards: |
For humans, cobalt compunds generally have low toxicity by ingestion, but produce vomiting. Cobalt is a suspected carcinogen.
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| Level in humans |
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| Blood: |
0.0002 - 0.04 mg dm-3 |
| Bone: |
0.01 - 0.04 p.p.m. |
| Liver: |
0.06 - 1.1 p.p.m. |
| Muscle: |
0.028 - 0.65 p.p.m. |
| Daily dietary intake : |
0.005 - 1.8 mg |
Total mass of element in average
[70 kg] person: |
3 mg |
Geological data
| Minerals: |
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| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Cobaltite |
CoAsS |
6.33 |
5.5 |
orth., met. steel grey |
| Erythrite |
CO3(AsO4)2.8H2O |
3.09 |
1.5 - 2.5 |
mon., adam./pearly crimson red |
| Glaucodot |
(Co, Fe) AsS |
6.04 |
5 |
orth., met. white |
| Linnaeite |
Co3S4 |
4.6 |
4.5 - 5.5 |
cub., met. grey/white in reflected light |
| Skutterudite |
CoAs3 |
6.5 |
5.5 - 6 |
cub., met. white/grey |
| Chief ore: |
cobaltite, skutterudite
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| World production: |
17000 tonnes/year |
| Main mining areas: |
Zaire, Morocco, Sweden, Canada |
| Reserves: |
n.a. |
| Specimen: |
available as foil, pieces, powder, rod and wire. CARE !
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| Abundances |
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| Sun: |
7.94 x 104 (relative to H = 1 x 1012) |
| Earth's crust: |
20 ppm |
| Seawater: |
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| Atlantic surface: |
n.a. |
| Atlantic deep: |
n.a. |
| Pacific surface: |
6.9 x 10-6 p.p.m. |
| Pacific deep: |
1.1 x 10-6 p.p.m. |
| Residence time:: |
40 years |
| Classification: |
scavenged |
| Oxidation state: |
II |
Other sizes and specifications on request
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