Demagnetizing Neodymium Magnets
Most recent answer: 04/26/2016
- Himanshu Kawatra (age 26)
It takes a big ac field to demagnetize those magnets at room temperature. You can demagnetize them by heating them to the Curie temperature, but that may be inconveniently high, e.g. 350°C. Another option is to heat to some lower temperature and apply a smaller ac field than would be needed at room temperature. Some of the specifications for temperatures and fields needed can be found on this commercial site:
By the way, I've found that electric toothbrush heads contain strong magnets, probably neodymium-based. I wonder if it would be practical to recycle those. I use them on my refrigerator door.
(published on 04/26/2016)