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Niobium single crystal 41Nb92.906
Discovered in 1801 by C. Hatchett at London, England.
[Greek: lithos = stone]
French: lithium
German: lithium
Italian: litio
Spanish: litio
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Description: Niobium is a shiny, silvery metal, which is soft when pure. It resists corrosion due to an oxide film on the surface. Niobium is attacked by hot, concentrated acids, but resists attack by alkalis, even when they are molten. Niobium is used in stainless steels.
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Metal single crystal properties
| State: |
single crystal |
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| Crystal structure: |
bcc |
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| Production method: |
Floating Zone |
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| Standard size: |
diameter 8-12mm
thickness 1-2mm |
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| Orientation: |
(100), (110) and (111) |
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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): |
C 25
H < 1
O 15
N < 5
Ag < 0.9
Al 3.6
As 0.29
Cl 0.66
Co 0.55
Cr 1.8 |
Fe 3.4
K 0.18
Li 0.22
Mg 0.45
Na 0.69
Ni 1
S 1.4
Si 17
Ta 180
Zn 0.48
Nb balance |
Further Materials properties
| Crystal structure: |
(cell dimensions/pm), space group
b.c.c. (a=329.86), Im3m |
| X-ray diffractions mass absorption coefficients: |
CuKa 153 (µ/r) / cm2g-1
MoKa 17.1 (µ/r) / cm2g-1
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| Neutron scattering length: |
0.7054 b/10-12 cm |
| Thermal neutron capture cross-section: |
1.15 sa / barns
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| Density: |
8.4 g/cm3 |
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| Melting point: |
2467.85 °C / 2741 °K |
| Boiling point: |
4741.85 °C / 5015 °K |
| Molar volume: |
10.84 cm3 |
| Thermal conductivity: |
53.7 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
7.07 x 10-6 K-1 |
| Electrical resistivity: |
12.5x10-8 [273 K] Wm |
| Mass magnetic susceptibility: |
+2.76 x 10-8(s) kg-1m3 |
| Young's modulus: |
104.9 GPa |
| Rigidity modulus: |
37.5 GPa |
| Bulk modulus: |
170.3 GPa |
| Poisson's ratio: |
0.397 GPa |
| Radii: |
Nb5+ 69; Nb4+ 74; atomic 143; covalent 134 |
| Electronegativity: |
1.6 (Pauling); 1.23 (Allred); 4.0 eV (absolute) |
| Effective nuclear charge: |
3.30 (Slater); 6.70 (Clementi); 9.60 (Froese-Fischer) |
| Number of Isotopes (incl. nuclear isomers): |
31 |
| Issotope mass range: |
86 -> 103 |
Biological data
| Biological role: |
none |
| Toxicity |
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| Toxic intake: |
n.a. |
| Lethal intake: |
LD50 (chloride, oral, rat)= 1500 mg kg-1 |
| Hazards: |
Niobium and its compounds may be toxic but there are no reports of humans beeing
poisoned. Niobium dust causes eye and skin irritation. |
| Level in humans |
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| Blood: |
0.005 mg dm-3 |
| Bone: |
<0.07 p.p.m. |
| Liver: |
0.14 p.p.m. |
| Muscle: |
0.14 p.p.m. |
| Daily dietary intake : |
0.02 - 0.6 mg |
Total mass of element in average
[70 kg] person: |
< 1.5 mg |
Geological data
| Minerals: |
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| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Betafite |
(Ca, U)2(Ti, Nb, Ta)2O6(OH) |
4.5 |
4 - 5.5 |
cub., waxy/vit. black/greenish |
| Columbite |
(Fe, Mn)(Nb, Ta)2O6 |
varies |
c. 6 |
orth., opaque sub.met. lustre |
| Fergusonite |
YNbO4) |
5.7 |
5.5 - 6.5 |
tet., vitreous, sub-met. black |
| Samarskite |
(Y, Ce, U, Fe)3(Nb, Ta, Ti)5O16 |
5.69 |
5 - 6 |
orth., vitreous/resinous black |
| Chief ore: |
columbite, samarskite, betafite; obtained as a by-product of tin-extraction.
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| World production: |
15 000 tonnes/year |
| Main mining areas: |
Australia, Zaire, Brazil, Russia, Norway, Canada, Madagascar |
| Reserves: |
n.a. |
| Specimen: |
available as foil, powder, rod, turnings or wire. Safe.
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| Abundances |
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| Sun: |
79 (relative to H = 1 x 1012) |
| Earth's crust: |
20 p.p.m. |
| Seawater: |
9 x 10-7 p.p.m. |
| Residence time:: |
n.a. |
| Oxidation state: |
V |
Other sizes and specifications on request
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