Iron monosilicide
Structures of left-handed and right-handed FeSi crystals. The top presentation shows the eight atoms of the unit cell. The middle shows polyhedra surrounding the iron atoms. The bottom show the presence of 3-fold screw axes.
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Names | |
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IUPAC name
Iron silicide
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Other names
Naquite, fersilicite
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Identifiers | |
3D model (
JSmol ) |
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ChemSpider | |
ECHA InfoCard
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100.031.506 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
FeSi | |
Molar mass | 83.931 g/mol |
Appearance | gray cubic crystals[1] |
Density | 6.1 g/cm3[1] |
Melting point | 1,410 °C (2,570 °F; 1,680 K)[1] |
Band gap | 0.05 eV (ind.) 0.14 eV (dir.)[2] |
8.5×10−6 emu/g[3] | |
Structure | |
Cubic[4] | |
P213 (No. 198), cP8 | |
a = 0.44827(1) nm
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Formula units (Z)
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4 |
Hazards | |
Flash point | Non-flammable |
Related compounds | |
Other anions
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Iron germanide |
Other cations
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Cobalt silicide Manganese silicide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Iron monosilicide (FeSi) is an
The structure is the prototype of the "iron monosilicide structure type", of
In the case of iron monosilicide, x = 0.13652 and y = 0.8424 (or −0.1576), or x = −0.13652 and y = 0.1576, so the seven silicon atoms around an iron atom are not all the same distance from the iron atom. Each silicon atom sits in a similar cage of iron atoms. The cages only have threefold rotational symmetry, with three slightly different interatomic distances between the central atom and the seven surrounding atoms (to 3 atoms, 3 atoms, and 1 atom respectively). There are right-handed and left-handed threefold screw axes without there being a symmetry element taking one to the other. (Threefold screw axes also exist in sodium chloride but are related by a mirror.) This means that iron monosilicide crystals exist in two different enantiomorphs, depending on the signs of x and y.[6]
In 1948 Linus Pauling investigated the nature of the bonds in iron monosilicide.[7]
See also
References
- ^ ISBN 9781498754293.
- S2CID 15970627.
- ^ .
- ^ .
- ^ "FeSi (B20) Structure". Encyclopedia of Crystallographic Prototypes. AFLOW.
- PMID 32132558.
- .