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Is there any chance of discovering more isotopes of Iron?

  1. Apr 11, 2009 #1
    I have checked Wikipedia and the National Nuclear Data Center and it looks like Iron (Fe) has 28 isotopes. There are 6 additional isotopes that come under the main ones (such as 52mFe under 52Fe) making the total of 34. My question is if there is any possibility that someday more Iron isotopes would be discovered?! Is the technology so advanced that all the isotopes have been discovered?! Or is there a chance that somewhere in universe there exist more isotopes?!

    I am not sure how they really manage to discover them.

    Thanks for answering my curious mind!
  2. jcsd
  3. Apr 11, 2009 #2
    My initial thought is that there are as yet to be discovered new isotopes.Some of these may be present in earthbound iron samples but remain undetected because the amounts are so small that they go beyond the present limits of resolution of mass spectrometers and the like.
  4. Apr 11, 2009 #3
    I suggest there is no more than what has been already discovered. There are 28 ones plus 6 high-spin isotopes.
  5. Apr 11, 2009 #4
    I don't think either of us can be sure as of yet but what may be safe to say is that the 28+6 is what has been detected at the present time.
  6. Apr 11, 2009 #5


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    There's a limit? Surely (in principle) you can always add/remove one more neutron?
  7. Apr 11, 2009 #6


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    Considering the half-lives of the lightest and heaviest Fe-isotopes are:

    Fe-45 t1/2 = 1.89 ms

    Fe-72 t1/2 > 150 ns

    In the case of Fe-72, it's not around long enough to add a neutron.

    Mn-44 t1/2 < 105 ns, so Fe-44 is likely to have similarly short half-life, or simply not be stable enough. Absorption of a neutron is not practical given the absence of Mn-43, and the fact that Mn-44 decays by e+ or ε, so Z decreases. An (n,p) reaction is not feasible due to the absence of Co-44, although Co-44, if is existed should decay by e+ or ε to Fe-44, which should also decay by e+ or ε.

    One could try a collide the appropriate isotopes of Al (Z=13) with the appropriate isotopes of Si (Z=14) to produce Co-44, e.g. collide Al-22 with Si-22 or Si-23 (or Al-23 with Si-21), depending on spallation of a neutron or not. However, one has to look at the half-lives of the reactant radionuclides Al-22 (t1/2 = 59 ms) and Si-22 (t1/2 = 29 ms) or Si-23 (t1/2 = 42.3 ms). The reactants have relatively short half-lives which makes it rather infeasible to use them.

    One could collide, Al-22 with Al-22, and assuming there is no loss of neutrons, one could obtain Fe-44. If there were spallation of n's involved, one might have to try using Al-23, on Al-22. Or one has to try lighter (Z-1, Z-2, . . .) isotopes onto heavier (Z+1, Z+2, . . .) isotopes (where Z=13), e.g. Mg on to Si. But same problem trying to make Co-44; the precursors have short half-lives. Using heavier stable isotopes of Al, Mg, Si, would required spallation of neutrons to obtain Fe-44 or Mn-44.

    One also has to look at the literature to see if the radionuclide as actually been experimentally created and detected, or is it simply a theoretical calculation. I seem to remember that the requirement to be included in the chart is that the radionuclide either exists or has been created.

    Perhaps Fe-44 exists very briefly in supernova.

    I'm not sure why one would do that given that there are no practical applications for extremely short-lived radionuclides.

    Furthermore, the metastable (m) states of radionulides are not considered separate isotopes. The are simply the same isotope in an excited state that has a probability of decaying by gamma-emission, without changing atomic number Z, or atomic mass A. So there are 28 identified isotopes of Fe, not 34.
  8. Apr 11, 2009 #7
    Thanks for the ideas and for clarifying things up. I understand that it's highly unlikely that there are more isotopes for Iron than those already discovered.

    I cannot truly understand why but I got some negative reactions from some ppl here.

    There is knowledge that I want to communicate to ppl here but the moderators are stopping me. Why this site should be deprived of open discussions about religion?! Science and religion are two aspects of society. Why putting a barrier?!
  9. Apr 11, 2009 #8


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    Because this is a science forum, not a religious forum. I saw what you tried to post, and honestly, it doesn't qualify as science.
  10. Apr 11, 2009 #9


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    This is a rather strange response to what I stated.

    There is nothing negative in what I stated. I gave an expectation based on the physics and reality, not the magical or wishful thinking. I think there is fiction or metaphysical speculation that one wants to communicate here, and that is unacceptable at PF.
    Last edited: Apr 11, 2009
  11. Apr 11, 2009 #10
    I am sorry Astronuc. I wasn't commenting on what you said as being negative. I thank you for the information you provided.
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