Is magnetic insulation possible? From what I have seen it is not. If so Why? Permanent magnets are not permanent? I read about that permanent magnets lose their magnetism after some time. What does this mean.How much time or usage does it take to make it a non magnet.


Yes, a sheet of a superconducting material will act as a magnetic screen because magnetic fields cannot penetrate into superconductors. Actually a plate of a simple ferromagnet is not a bad magnetic screen and will block most of the magnetic field, though not all. As Jon Custer points out, there is a high relative permittivity ferromagnet called mu metal that is often used for magnetic shielding.

Your second question is a duplicate of Does a permanent magnet loose its magnetism?.

  • $\begingroup$ Well if there exists am happy to know. Thanks for your response. $\endgroup$
    – user7063
    Jul 20 '14 at 18:15
  • $\begingroup$ So called Mu metal is used to shield magnetic fields. It isn't insulation per se, but does do a good job of redirecting/confining magnetic field lines. $\endgroup$
    – Jon Custer
    Jul 20 '14 at 18:18
  • $\begingroup$ I would like to confirm once again about it being insulators to be exact.The other places I read people have mentioned there exist nothing like magnetic insulator.Looking your profile scores I doubt you being wrong :) $\endgroup$
    – user7063
    Jul 20 '14 at 18:33
  • $\begingroup$ @user7063: There is no such thing as a perfect insulator, either magnetic or electrical, but superconductors come pretty close to perfect magnetic insulators (though a superconductor will cease to be superconducting if you make the magnetic field too strong). $\endgroup$ Jul 20 '14 at 18:36
  • $\begingroup$ I was thinking of some neodymium magnetd for some fun experiments.What should I be using . ?One that is easily available as an insulator. $\endgroup$
    – user7063
    Jul 20 '14 at 19:00

Here’s the real answer to your questions. Super conductors don’t insulate magnetic fields completely therefore they don’t insulate magnetic fields. According to my experimental research on fluxons, superconductors, atoms and magnetic fields there is something called fluxons that passes through a superconductor. All these fluxons are is just condensed invisible photons. They slide through near the edges of the superconductor due to the highest magnetic flux being on the edges. Just like on permanent and electromagnets.

For permanent magnets I have done yet more experimental research on this type of stuff. To answer your questions on this we can dig deep or go shallow. If we end up going shallow there’s a possibility that you won’t understand what I’m saying, so we will go deep into this topic.

The usage time can vary quite a bit due to accidentally dropping or, and attaching magnets together. Basically any vibrations will accelerate the time it takes for a permanent magnet to lose its magnetic field but not its magnetic properties.

In fact due to popular belief many say that extreme heat will alter the permanent magnet to then lose its magnetic properties forever. But that’s not true. According to my experimental data where I exposed neodymium, SmCo, AlNiCo, and ferrite (ceramic) magnets to melting temperatures and made them a liquid. I then let them cool down and the next thing I knew was that the magnets expectedly lost their magnetism.

But when I heated them up with a colder flame from a typical lighter and exposed them to a magnetic field of 3 Tesla I was able to remagnetize the magnets back to normal.

But back to the question.

So how much time does it take for a permanent magnet to lose its name for being a magnet?

Well this varies VERY widely for many magnets. But let’s take the Neodymium magnet (NdFeB)(Neodymium + Iron + Boron) for example. A Neodymium magnet loses 1/10th of its magnetic field over the span of 10 years. Then that means that over the span of 100 years it will lose 10/10th’s of its magnetic field over 100 years. Of course under optimum or non altering conditions.

Please let me know if you have more questions and I’ll answer them to my best knowledge.


Note: A magnet is no longer considered a magnet if there is a negligible or small amount of magnetic field emitting from the source.


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