About domain theory of ferro magnetism

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Discussion Overview

The discussion revolves around the domain theory of ferromagnetism, focusing on the alignment of magnetic dipoles and the role of quantum mechanical effects, particularly the exchange interaction, in ferromagnetic materials. Participants seek clarification on the underlying principles and mechanisms involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant notes that classical electromagnetism suggests nearby magnetic dipoles align in opposite directions, leading to cancellation of their magnetic fields.
  • Another participant introduces the concept of the exchange interaction as a quantum mechanical effect that causes ferromagnetic materials to align in the same direction.
  • The Pauli exclusion principle is mentioned as a factor that influences the behavior of electrons in adjacent atoms, particularly regarding their spins and spatial distribution.
  • A participant requests further explanation on how parallel spins lead to a different distribution of electric charge compared to opposite spins.
  • Another participant provides a diagram to illustrate the cancellation of magnetic moments in a specific configuration.

Areas of Agreement / Disagreement

The discussion reflects a lack of consensus, with participants expressing various levels of understanding and seeking clarification on specific aspects of the domain theory and associated quantum effects.

Contextual Notes

Some assumptions regarding the behavior of magnetic dipoles and the implications of quantum mechanics remain unaddressed, and the discussion does not resolve the complexities of the concepts involved.

A Dhingra
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hi ...
i want to ask about domain theory of ferromagnetism...
first of all , According to classical electromagnetism, two nearby magnetic dipoles will tend to align in opposite directions, so their magnetic fields will oppose one another and cancel out.
how does this happen?
after this , ...However in a few the ferromagnetic materials, they tend to align in the same direction because of a quantum mechanical effect called the exchange interaction. The Pauli exclusion principle says that two electrons with the same spin cannot also have the same "position". Therefore, under certain conditions, when the orbitals of the unpaired outer valence electrons from adjacent atoms overlap, the distribution of their electric charge in space is further apart when the electrons have parallel spins than when they have opposite spins.

With parallel spin the charges are further apart than that due to opposite spin . . . . how ? ? ?

please explain this to me...
thanks for any help...
 
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hello...
someone... please help me with this ...
 
am i on the wrong category that no replies yet...
 
U try to continue with ur questions in the other thread only.
 
but what i wanted to ask was there to some extent ..so i continued there...
ok... can you explain me the first part of the question here... please
 
...According to classical electromagnetism, two nearby magnetic dipoles will tend to align in opposite directions, so their magnetic fields will oppose one another and cancel out.
how does this happen?
North pole (N) attracts South pole (S). Keep this in mind and take a look at the attached diagram. I hope it will be self explanatory.
Cheers
 

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    magnets.png
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The magnetic moments are canceled in the second configuration.
 
Ok i got it... thanks
 

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