Talk:Rare-earth magnet

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How do they work?[edit]

I wonder if someone could add a simplified explanation of how rare earth magnets work on an atomic scale. Do they use the same exchange energy mechanism as other ferromagnets? Why are they so much stronger? Who invented them? Do the neodymium and samarium types work the same? If not, I guess the explanation should be put on the separate pages for those magnets. --Chetvorno 21:27, 11 August 2007 (UTC)

Safety Considerations[edit]

I plan to update have updated the safety considerations portion of the neodynium magnet section. the verbage used seems overly dramatic, as well as a bit misleading. I think the safety considerations of using Nd magnets falls well within the bounds of commons sense, and does not warrant a such a dramatic warning. --Voltaic (talk) 06:49, 18 September 2008 (UTC)


Please condsider changing the applications section where it lists "roller coaster launches" as an application for these magnets. Any research into roller coaster launches will see that they use eddy currents which require the use of an alternating magnetic field such as created from a coil powered by an alternating current, and a paramagnetic plate such as bronze, and no permanent magnets are used. Perhaps the auther was thinking of eddy current brakes which do make use of such magnets, brakes and launches are two different things. (talk) 04:24, 15 December 2009 (UTC) Sandy

Good catch! Since you found it, and obviously have done the research, maybe you could make the changes. --ChetvornoTALK 07:32, 16 December 2009 (UTC)

Coin collectors use neodymium magnets to detect counterfeit silver dollars.(pre-1930's 90% silver.) If you hold a genuine coin at a 45 degree angle, and put the magnet at the top of the coin, it will slide slowly to the bottom and off the coin.(it appears to have a weak magnetic attraction) With a counterfeit coin, it will either stick to the coin, or quickly slide off.(no magnetic attraction at all) Yogisd1 (talk) 05:38, 4 September 2015 (UTC)Yogisd1

Incorrect chemical description[edit]

I am under the impression that the second type of Samarium magnet should not be "Sm(Co,Fe,Cu,Zr)7" but "Sm2(Co,Fe,Cu,Zr)17". Can anyone confirm? —Preceding unsigned comment added by (talk) 04:02, 2 March 2010 (UTC)

If you can find a reliable source, fix it. Ginbot86 04:56, 2 March 2010 (UTC)


This statement "The stronger magnetic fields can...magnetize the shadow masks of CRT type monitors at a significant distance." is questionable. There is no indication what "significant distance" is, or how it compares to weaker magnets. Given that field intensity falls off as the inverse cube of distance, it is unclear how much greater a distance this would be for comparatively sized rare-earth magnets. —Preceding unsigned comment added by (talk) 02:23, 14 October 2010 (UTC)

Verification of Magnet strength[edit]

How often should you verify the magnet strength is still effective? We have a gauss measurment system but not sure how often it needs to be done? If it is done monthly or yearly and it fails would all product back to that last month or year be subject to foreign material? — Preceding unsigned comment added by (talk) 22:17, 11 February 2013 (UTC)

What is missing from this article is the most important application, or at least as far as the Air Force is concerned. Specifically developed by the Air Force to improve propulsion of their top secret flying saucers to better use free energy. They don't want the public to know that energy is free. — Preceding unsigned comment added by (talk) 19:45, 6 December 2013 (UTC)