Getting Through Stickey Spots?

[beedees]

Check this link out. It's a material called Giron that has some very interesting properties.

http://www.lessemf.com/mag-shld.html

It's $35 for a 2'X1' piece. It can be cut. A bit costly, yet seems like a very useful addition to ones magnetism experimentation lab.

j

the keyword here is ELECTRO-Magnetic....Mu-metal and Giron are effective for their intended uses, but rather hopeless for effectivley sheilding P.M. I have  had some luck with surrounding P.M. with a powdered iron matrix, but don't know yet what the long-term effect on the magnets will be. (Probably not good.) The only sure thing I have found is separation. Working on a new idea now.

[gyulasun]

Hi Folks,

There is an interesting property of Giron which I think is important for effectively use Giron as a shield, see this text from this page: http://www.lessemf.com/mag-shld.html

"A further distinction is that the magnetic properties of GIRON are anisotropic... that is they are not the same in all directions. Permeability along the long axis is excellent, across the long axis good, and perpendicular to the surface it is slight. Thus magnetic shielding effect can be increased or decreased by merely rotating the orientation of the shield. Very unique!"

Somehow this property could be utilized for our purposes here, by good mechanical arrangement and selecting thickness, magnet sizes etc.

There is another material called Pyrolytic Graphite, (PG), see this link:
http://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html

This could also be used for shielding and also has got similar property like I referred to above in case of Giron. PG is available from Scitoys.

Finally see this link for another magnetic shielding material (described in the US patent):  http://www.overunity.com/index.php/topic,2217.msg29095.html#msg29095

Because neither pyrolytic graphite nor the mixture material from the US patent is attracted by permanent magnets (they are non ferromagnetic, unlike mumetal or Giron) they may serve better shielding materials for our purposes here.

Regards
Gyula