Isotopes of iron

Isotopes of iron (26Fe)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
54Fe 5.85% stable
55Fe synth 2.73 y ε 55Mn
56Fe 91.8% stable
57Fe 2.12% stable
58Fe 0.28% stable
59Fe synth 44.6 d β− 59Co
60Fe trace 2.6×106 y β− 60Co
Standard atomic weight Ar°(Fe)

Naturally occurring iron (26Fe) consists of four stable isotopes: 5.845% of 54Fe (possibly radioactive with a half-life over 4.4×1020 years),[4] 91.754% of 56Fe, 2.119% of 57Fe and 0.286% of 58Fe. There are 28 known radioactive isotopes and 8 nuclear isomers, the most stable of which are 60Fe (half-life 2.6 million years) and 55Fe (half-life 2.7 years).

Much of the past work on measuring the isotopic composition of iron has centered on determining 60Fe variations due to processes accompanying nucleosynthesis (i.e., meteorite studies) and ore formation. In the last decade however, advances in mass spectrometry technology have allowed the detection and quantification of minute, naturally occurring variations in the ratios of the stable isotopes of iron. Much of this work has been driven by the Earth and planetary science communities, although applications to biological and industrial systems are beginning to emerge.[5]

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  2. ^ "Standard Atomic Weights: Iron". CIAAW. 1993.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ Bikit, I.; Krmar, M.; Slivka, J.; Vesković, M.; Čonkić, Lj.; Aničin, I. (1998). "New results on the double β decay of iron". Physical Review C. 58 (4): 2566–2567. Bibcode:1998PhRvC..58.2566B. doi:10.1103/PhysRevC.58.2566.
  5. ^ N. Dauphas; O. Rouxel (2006). "Mass spectrometry and natural variations of iron isotopes". Mass Spectrometry Reviews. 25 (4): 515–550. Bibcode:2006MSRv...25..515D. doi:10.1002/mas.20078. PMID 16463281.