Talk:Ferromagnetism

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How do rare earth magnets work?[edit]

Isn't Neodymium ferromagnetic? It is used in neodymium magnets, some of the most powerful permanent magnets ever made, and according to the page on Neodymium, it is a ferromagnetic. 72.45.61.218 19:09, 6 April 2007 (UTC)

Yes, I was wondering if someone could add a simplified explanation of how rare earth magnets differ from previous permanent magnets. What makes them so much stronger? I assume they work by the same 'exchange energy' mechanism as other ferromagnets. And who invented them? This doesn't seem to be addressed in Rare earth magnet or Neodymium magnet or elsewhere. --Chetvorno 21:59, 11 August 2007 (UTC)

I think it may be because rare earths can have more unpaired electrons than transition metals, as there are more orbitals that can be partially filled (7 f orbitals vs 5 d orbitals). --Itub 13:39, 10 October 2007 (UTC)
For the rare earth magnets two things come together: a high moment for the ions and large magnetic anisotropy. This translates to high saturation and high coercivity.--Ulrich67 (talk) 22:49, 2 January 2012 (UTC)
There is a little material on rare earth magnets in Magnetism. RockMagnetist (talk) 19:14, 3 January 2012 (UTC)

Interacting magnetic fields[edit]

There is a lot of discussion of the properties of various types of magnetic materials as to how to maximize the internal properties or the materials. However there is practically no discussion of what controls the intensity of magnetic force activity in the interacting field spacial volume. If a suspended magnet is swung like a pendulum over an opposing polarity magnetic the interaction of the fields will control the physical activity (motion) of the moving magnet at some distance. The question is as to how this magnetic force is capable of being extended so as to continue to act is not discussed.WFPM (talk) 23:54, 16 February 2012 (UTC)


Diagram request[edit]

I think this article could benefit from a hysteresis diagram like found in standard textbooks and like can be found in the ferroelectricity article:

http://en.wikipedia.org/wiki/Ferroelectricity

129.63.129.196 (talk) 15:59, 19 November 2012 (UTC)


And then you can write something like my removed sentence, but maybe more clarified: "The most important parameters of the ferromagnetic material constitute its magnetic hysteresis loop." Because on that diagram one can see magnetic parameters of a given ferromagnetic material, determining its possible utilization: coercivity and so on. Niuthon (talk) 07:33, 24 July 2014 (UTC)

A section on hysteresis would be good, with a diagram and a discussion of some of the hysteresis parameters. Even if such a section is created, though, there remain a couple of problems with your statement . First, the "most important" label is arguable: one can also talk about more fundamental parameters like the magnetocrystalline anisotropy constant. Also, you're really talking about a particular hysteresis loop, the main loop. Clearly that must be clarified in the body of the text before adding a statement to the lead. Note also that, per MOS:LEAD, the lead should summarize the content, not add significant new information. RockMagnetist (talk) 14:55, 24 July 2014 (UTC)

Domain images[edit]

We now have a superabundance of domain images, spilling down past the next two sections and into References. Do we really need all of them? I like the first and fourth images, but the second and third are hard to interpret. RockMagnetist (talk) 17:23, 19 December 2012 (UTC)

I agree, the second and third should be removed. -ChetvornoTALK
There being no objection in two years, I have removed the images. RockMagnetist (talk) 14:58, 24 July 2014 (UTC)