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Magnetization of a gas

  1. Mar 24, 2014 #1

    bobie

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    What happens if we apply a magnetic field to a gas in vacuum, (like H or He)?,
    do the atoms get aligned like in ferromagnetic material and produce in their turn a strong magnetic field?,
    if they don't, why so?

    Thanks
     
  2. jcsd
  3. Mar 24, 2014 #2

    PhysicoRaj

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    It depends on which gas it is. Most of the gases are diamagnetic, some paramagnetic and ferromagnetic gases are very rare.
     
  4. Mar 24, 2014 #3

    bobie

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    Can you give me an example of ferromagnetic gas? and what about H?
    Since in a gas atoms are not bound (as in iron) what determines its reaction to a magnetic field?
     
    Last edited: Mar 24, 2014
  5. Mar 24, 2014 #4

    UltrafastPED

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  6. Mar 24, 2014 #5

    bobie

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    Thanks for the interesting ling, Ultrafast, If I got it right alignment can occur at extremely low temperatures, because repulsive collisions between atoms are stronger than the magnetic force, and I suppose in laboratoty you cannot get a sufficiently strong magnetic field.

    I hope you could explain a couple o obscure points
    in your wiki article they say "The permanent moment generally is due to the spin of unpaired electrons in atomic or molecular electron orbitals (see Magnetic moment). "
    - is the magnetism dependent only on the electron spin (which is very weak : [itex]\hbar[/itex]?
    doesn't the B field produced by the standing wave ,which is a lot stronger, play any tole at all?
    - In QM, I learned, the electron wave id 3-D, how can the electron spin be stuck only in one direction
    in such model?
    Thanks
     
    Last edited: Mar 24, 2014
  7. Mar 24, 2014 #6

    UltrafastPED

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    Electron spin - the Pauli exclusion principle permits two electrons in the same "quantum state" = "orbital" if they have opposite spin.

    The spin of an electron has an associated magnetic moment - thus the unpaired electrons are the most important source for magnetic fields at the atomic/molecular level.
     
  8. Mar 25, 2014 #7

    bobie

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    Thanks, ultrafast, I am thinking of H to take the simplest case

    I meant:
    yes, the spin does have a magnetic moment, [itex]\mu[/itex](e)
    - does it have also an associated magnetic field B(e)?, and,
    - does the magnetic field generated by the orbit B(o) and its associated magnetic moment [itex]\mu[/itex](o) play any role in the magnetization ?
    Thanks again
     
  9. Mar 25, 2014 #8

    UltrafastPED

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  10. Mar 30, 2014 #9

    bobie

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    We know that in QM the value of the spin momentum L(e) and the value of the orbital momentum L(o)(http://en.wikipedia.org/wiki/Orbital_motion_(quantum)#Orbital_Angular_Momentum) are the same as in classical model = [itex]\hbar[/itex], the value of [itex]\mu[/itex]e is [itex]\hbar*2.0023[/itex] (ge), right?

    What is the value of B(e) and B(o) in neutral H atom according to QM model or current theory? how do we calculate it?
     
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