Magnetic sheild design

[Floor]

An idea I had some time ago, and also one that I have seen others express on the forum, is to use graphene as a magnetic shield.

A design using multiple and spaced layers of graphene might be better than a single layer.

Your ideas  thoughts on this.


                                               Floor

[gyulasun]

Somehow a piece of graphene sould be obtained and tested between a magnet and a soft iron piece to feel its magnetic shielding properties first. 
I am not aware of any meaningful report on that, unfortunately. Perhaps the price is high for graphene I wonder.

Another such 'promising' material has been pyrolitic graphite but its shielding properties are still too small.
http://sci-toys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html
Your drawing reminds me to a slightly different setup  shown by member Tao some years ago here:
http://www.overunity.com/4172/overunity-device-using-magnets-in-the-1920s/msg80515/topicseen/#msg80515

Gyula

[Floor]

@gyulasun

         thanks for the links

   Corrected, It should be Pyrolitic graphite.

Sony sells a variety of flexible sheets down to 25 micro meters.

Just wondering if the diamagnetizm can be increased by layering.

[gyulasun]

Hi Floor,

Yes diamagnetism can be increased by layering but the effect would still be very small i.e. flux could still penetrate strongly via the layers I am afraid.  But it should be tested of course, just order some sheets and test them, sorry that I have not done so but what I have read so far about its properties, it has not convinced me...
This link may give some more info: http://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitation   
Somewhere I read (I cannot find it now) that this material (Pyrolitic graphite) behaves differently for flux coming from different directions and it has a definite orientation to give the highest diamagnetic property (but this still a small effect).

Gyula

[Floor]

@gyulasun

I hope the sun shines brightly in Gyula today, thanks for the replys.

I also, do not find anywhere that says single layer graphene is diamagnetic.  Pyrolytic graphite is layers of graphene that have some covalent bonding between layers.

Is it  the structure / motions of the covalently shared electrons that causes the diamagnetism   ?

Would 3 layers of covalently bonding graphene be 2 x more diamagnetic or would it be less diamagnetic than 2 layers, or would it be the same.

Would there be partial cancellation of the diamagnetizm  in three layers?

Would two ,layers of graphene covalently bonding separated from two other layers of covalently bonded graphene, be more diamagnetic than if all 4 layers were bonded.

I don't have an answer to my questions.

But, I read that, pyrolytic graphite would need to be orders of magnitude more diamagnetic to be useful as a magnetic shield in an all magnet motor.


                                                cheers
                                                      floor