An iron–nickel alloy, nickel–iron alloy, or abbreviated FeNi and NiFe, is a group of alloys that mostly consist of the elements nickel (Ni) and iron (Fe). The acronym NiFe is used to refer to various chemical reactions that involve a nickel–iron catalyst or component, or in geology, to refer to the general composition of planetary cores (including Earth's).
Astronomy and geology
Iron and nickel are notable for being the final elements produced by stellar nucleosynthesis, and thus the heaviest elements that do not require a supernova or similarly cataclysmic event for formation. Iron and nickel are therefore the most abundant metals in metallic meteorites and in the dense-metal cores of planets such as Earth.
Chemistry and technology
The affinity of nickel (atomic number 28) and iron (atomic number 26) for one another produce natural occurring alloys, a large number of commercial alloys, and provide a complex electron environment for catalyzing chemical reactions.
The following table is an overview of different iron–nickel alloys. Naturally occurring alloys are a type of mineral and called native elements or native metals. Some of the entries have more than one crystal structure (e.g. meteoric iron is a mixture of two crystal structures).
|Name||Description||Chemical formula/Weight percent Ni|
|Antitaenite||A native metal found in meteorites.||Fe3Ni|
|Austenite||A special allotrope of steel that is stabilized with nickel.|
|Awaruite||A native metal found in serpentinites and meteorites.||Ni2Fe to Ni3Fe|
|Earth's core||Earth's core is composed of an iron–nickel alloy.||about 5.5%|
|Elinvar||A steel whose elasticity does not change with temperature.||36% (also 5% chromium)|
|Invar||A steel with very low thermal expansion.||36%|
|Kamacite||A native metal found in meteoric iron||Fe0.9Ni0.1|
|Maraging steel||A strong, malleable variant of steel||15 to 25%|
|Meteoric iron||A combination of mostly kamacite and taenite and minor amounts of tetrataenite, antitaenite and awaruite.||5–30%|
|Mu-metal||A metal with high magnetic permeability.||77%|
|Planetary core||Planets, Moons and Planetesimals also can have cores made of an iron–nickel alloy.||Various|
|Taenite||A native metal found in meteorites||NiFe|
|Telluric iron||A native metal found on earth (not extraterrestrial)||Fe (but 0.05 to 4% nickel)|
|Tetrataenite||A native metal found in meteorites.||FeNi|
|Look up nife in Wiktionary, the free dictionary.|
- Wannier, P G (1980). "Nuclear Abundances and Evolution of the Interstellar Medium". Annual Review of Astronomy and Astrophysics 18: 399. Bibcode:1980ARA&A..18..399W. doi:10.1146/annurev.aa.18.090180.002151.
- Mason, Brian Harold (1971) Handbook of Elemental Abundances in Meteorites Gordon and Breach, New York, ISBN 0-677-14950-6
- Pardo, A; De Lacey, AL; Fernández, VM; Fan, HJ; Fan, Y; Hall, MB (2006). "Density functional study of the catalytic cycle of nickel-iron NiFe hydrogenases and the involvement of high-spin nickel(II)". Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry 11 (3): 286–306. doi:10.1007/s00775-005-0076-3. PMID 16511689.
- "Mindat Antitaenite". Mindat. Retrieved 9 January 2013.
- Lin, Jung-Fu (1 January 2002). "Iron-Nickel alloy in the Earth's core". Geophysical Research Letters 29 (10). Bibcode:2002GeoRL..29.1471L. doi:10.1029/2002GL015089.