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Silicon single crystal 14Si28.086
Discovered in 1824 by J.J. Berzelius at Stockholm, Sweden.
[Greek: lithos = stone]
French: lithium
German: lithium
Italian: litio
Spanish: litio
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Description: Black amorphous silicon is obtained by the reduction of sand (SiO2) with carbon. Ultrapure crystals if silicon have a blue-grey metallic sheen. Bulk silicon is unreactive towards oxygen, water and acids (exept HF), but dissolves in hot alkalis. Silicon is used in semiconductors, alloys and polymers.
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Metal single crystal properties
| State: |
single crystal |
| Crystal structure: |
diamond |
| Production method: |
Czochralski, Floating zone |
| Standard size: |
Diameter 20-80mm
thickness 1mm |
| Orientation: |
(110) and (111) |
| Orientation accuracy: |
<2°, <1°, <0.5° or <0.1° |
| Polishing: |
as cut, one or two sides polished |
| Roughness of surface: |
<0.03µm |
| Purity: |
99.999% |
Further Materials properties
| Crystal structure: |
(cell dimensions/pm), space group
cubic (a=543.07), Fd3m, diamond structure
(a=486.6, c=285.5), I41/amd
(a=664), Ia3
(a=380, c=628), P63/mmc
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| X-ray diffractions mass absorption coefficients: |
CuKa 60.6 (µ/r) / cm2g-1
MoKa 6.44 (µ/r) / cm2g-1
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| Neutron scattering length: |
0.41543 b/10-12 cm |
| Thermal neutron capture cross-section: |
0.171 sa / barns
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| Density: |
2.33 g/cm3 |
| Melting point: |
1409.85 °C / 1683 °K |
| Boiling point: |
2354.85 °C / 2628 °K |
| Molar volume: |
12.06 cm3 |
| Thermal conductivity: |
148 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
4.2 x 10-6 K-1 |
| Electrical resistivity: |
0.001x10-8 [273 K] Wm |
| Mass magnetic susceptibility: |
-1.8 x 10-9(s) kg-1m3 |
| Young's modulus: |
113 GPa |
| Rigidity modulus: |
39.7 GPa |
| Bulk modulus: |
n.a. GPa |
| Poisson's ratio: |
0.42 GPa |
| Radii: |
Si4+ 26; Si4- 271 atomic 117; covalent 117; van der Waals 200 |
| Electronegativity: |
1.90 (Pauling); 1.74 (Allred); 4.77 eV (absolute) |
| Effective nuclear charge: |
4.15 (Slater); 4.29 (Clementi); 4.48 (Froese-Fischer) |
| Number of Isotopes (incl. nuclear isomers): |
11 |
| Issotope mass range: |
24 -> 34 |
Biological data
| Biological role: |
Silicon is essential to some species and possibly to humans. |
| Toxicity |
Non-toxic as silicon, silicon dioxide or silicate. |
| Hazards: |
The fibres of some silicates, such as asbestos-type minerals, are carcinogenic. |
| Level in humans |
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| Blood: |
3.9 mg dm-3 |
| Bone: |
17 p.p.m. |
| Liver: |
12 - 120 p.p.m. |
| Muscle: |
100 - 200 p.p.m. |
| Daily dietary intake : |
18 - 1200 mg |
Total mass of element in average
[70 kg] person: |
c. 1 g |
Geological data
| Minerals: |
The earth's crust is composed primarily of silicate minerals. In this table only varieties of silicon dioxide (silica) are listed. |
| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Cristobalite |
SiO2 |
2.33 |
n.a. |
tet., vitreous/white |
| Opal |
SiO2.nH2O |
2 |
5.5 - 6.5 |
amor., transp./col./white |
| Quartz |
a-SiO2 |
2.655 |
7 |
rhom., vit., colourless |
| Tridymite |
SiO2 |
2.26 |
7 |
mon., vit., colourless/white |
| Chief ore: |
quartz (most common mineral on earth); also talc, mica.
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| World production (tonnes/year): |
5000 (electronic grade, i.e. pure silicon); 480 000 (metallurgical grade silicon); 3.4 x 106 (ferrosilicon) |
| Main mining areas: |
talc in Austria, Italy, India, South Africa, Australia; mica in Cananda, USA, India, Brazil |
| Reserves: |
unlimited |
| Specimen: |
available as powder, pieces or lumps. Safe.
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| Abundances |
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| Sun: |
4.47 x 107(relative to H = 1 x 1012) |
| Earth's crust: |
277 100 p.p.m. |
| Seawater: |
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| Atlantic surface: |
0.03 p.p.m. |
| Atlantic deep: |
0.82 p.p.m. |
| Pacific surface: |
0.03 p.p.m. |
| Pacific deep: |
4.09 p.p.m. |
| Residence time:: |
30 000 years |
| Classification: |
recycled |
| Oxidation state: |
IV |
Other sizes and specifications on request
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