Physics Question #4497
Marty Ellis, a 39 year old male from Pittsburgh asks on December 27, 2008,
Can a sintered ore magnet be re-magnetized in a different configuration of its poles? Does it need be heated to its Curie point to be easily remagnetized differently?
viewed 14806 times
Yes, the poles of a magnet can be changed by exposing the magnet to a very high magnetic field in a new direction. Many of the best magnets are sintered--densified from powder by heating at high temperature, often under pressure. If the magnet is a neodymium magnet, at room temperature you will need a strong pulse magnetizer to provide enough field. However, if you heat the magnet significantly, even a modest magnetic field can magnetize the magnet in a new direction.
Some sintered magnets are "anisotropic" with a strongly favored axis of magnetization. Such magnets can be reversed with a sufficiently high reverse field (or a modest reverse field at high temperature) but cannot easily be magnetized in directions transverse to the preferred axis.
Add to or comment on this answer using the form below.
Note: All submissions are moderated prior to posting.
If you found this answer useful, please consider making a small donation to science.ca.