What does magnetizing to saturation mean in terms of magnetic properties?
All “magnetizable” materials are at all times as fully magnetized as their thermal state permits. This is because orbiting unpaired electron spins are the source of atomic magnetic moments. These fully magnetized atomic magnets assemble themselves into clumps, or domains, with the same orientation. The domains then orient themselves to cancel each other so there is no measurable external magnetic field. Magnetizing is the process of turning all domains to a common alignment so the magnet exhibits an external magnetic field. The energy required to magnetize a material depends on a number of factors, and the amount of energy retained is related to the geometry and coercivity of the magnet material. Magnetizing to saturation implies that all domains are to be rotated into common alignment. This is impossible because the energy required increases asymptotically as the level of magnetization increases. In the past, the generally accepted criteria for “full saturation” was that there should
