Domain Walls in bar Magnets

Most recent answer: 10/22/2007

Q:
I am en engineer in the field of non-chemical fluid conditioning. With respect to a bar magnet, what are the implications of the internal Bloch wall specifically on the shape of the external magnetic field ? Why ?
- FRED
Aenertec America, USA
A:
In any standard magnet, there are lots of internal domain walls. They are very important for determining the magnetic field on a microscopic scale, and (by getting stuck on defects) for keeping the material from losing its magnetization. However, the external field can be treated well by ignoring the microscopic details and treating the magnet as a block of material with uniform magnetization, i.e. averaging over many domains.

Mike W.

(published on 10/22/2007)