I have read that certain materials, specifically ones with distinct magnetic properties, can influence the way magnetic field behaves around a magnet.
If you were to place a disc magnet inside an aluminum "cup," which covers the back and sides of the disc but not the front, would the magnetic field be affected in a measurable way? Specifically, would the field be any stronger at the front of the magnet, than if it were not inside the aluminum cup?
I suspect that the effect would be scientifically measurable, but mechanically insignificant for the purpose of attaching a ferric object to the magnet.
Also, can anyone recommend any scholarly literature on this subject?