How does an magnetic domain align?

  • Thread starter Thread starter Arceus74
  • Start date Start date
  • Tags Tags
    Domain Magnetic
Click For Summary
A magnetic domain aligns when an external magnetic field is applied, causing the magnetic moments of atoms to become unbalanced. Atoms can have a net magnetic moment due to half-filled electron shells, which is why some D block elements exhibit magnetism. The exchange interaction between neighboring spins often leads to clusters of aligned spins, forming domains. Without an external field, these domains may point in random directions, resulting in an unmagnetized material. When the external field is removed, materials like soft iron revert to a state of random domain orientation, leading to negligible macroscopic magnetization.
Arceus74
Messages
30
Reaction score
0
I have these assumptions please correct me if they are wrong:)
1)A particle has mass,electric charge and magnetic moment.
2)Somehow in a atom the net magnetic moment of all the particles including protons and electrons get canceled out and becomes neutral.However for half-filled electron shells there is some magnetic moment which makes the atom magnetically positive.
3)That is why some of the D block elements are magnetic.
4)When external magnetic field is applied the domains align.
In that case if we apply a magnetic field and the domains align it means that microscopically the electrons orientation or direction also changes,which makes the magnetic moment unbalanced right?
Please explain how does the magnetic moment is changing?
 
Physics news on Phys.org
There is a very strong exchange interaction which causes neighboring spins to often be already aligned. This can create a cluster of atoms aligned with aligned spins which is a domain. The magnetization of individual domains can point in somewhat random directions with no externally applied field, and the macroscopic effect is that the material is unmagnetized. Upon applying an external magnetic field, many of the domains can align themselves with the applied field, (which is energetically favorable since the energy ## E=-\mu \cdot B ##), and the material is strongly magnetized. In some materials, when a high level of magnetization occurs, the external field can be removed and essentially the internal magnetic field (which can be computed from the bound magnetic surface currents) maintains the alignment off the spins and a permanent magnet results. For reasons that are somewhat obscure, in soft iron, a permanent magnet does not occur, but instead, when the external field is removed, the energetically preferred state is one of a bunch of somewhat randomly oriented domains, with the net macroscopic magnetization being small or near zero. Perhaps others can add to and/or correct my explanation. The magnetism is a rather complex subject, and a couple of the more authoritative books on the subject can get so mathematically detailed that the explanations they offer are difficult to follow in detail.
 

Similar threads

  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
447
  • · Replies 14 ·
Replies
14
Views
2K
Replies
5
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 9 ·
Replies
9
Views
4K