How many times can split a a magnet?

Answer 1

In theory a magnet can be split infinitely, and its parts will retain the dipole (assuming the cutting process doesn't demagnetize it).

There will, however, be a limit based on the fragment size of the alloy. Perhaps microscopic.

The magnetic field is based on the electron spin characteristics of the electrons around atoms. So, in theory the smallest magnet would be a single atom.

However, for a permanent magnet, as far as I can tell, it derives its properties from interactions in the electron spin between neighboring atoms. And, most "permanent magnets" at room temperature are alloys with an amorphous structure.

So while the basic alloy structure would require 2 or 3 atoms, more realistically it would probably require a few hundred or a few thousand individual atoms to maintain the locked spin nature of the atoms. Even so, that would lead to a particle size that would push the limits of light microscopy.

Near absolute zero, the properties of many materials change, and it may be possible to approach the elusive one or two atom magnet, or small single molecule magnet. But, the meaningfulness of the orientation of the parent magnet may be lost.

Answer 2

A magnet can be split into smaller pieces multiple times, theoretically infinitely, as long as the force required to separate the pieces is greater than the magnetic attraction holding them together. However, splitting a magnet into very small pieces may result in the loss of its magnetic properties.