Do magnets wear out?

21st October 2010

Asked by: BARNEY COLLINS, BY EMAIL

So-called permanent magnets are constructed from materials made up of magnetic domains, in which atoms have electrons whose spins are aligned with each other. This alignment is damaged over time, principally as the result of heat and stray electromagnetic fields, and this weakens the level of magnetism. The process is very slow, however: a modern samarium-cobalt magnet takes around 700 years to lose half its strength.

GOT A QUESTION?
Scratching your head over a burning scientific conundrum? submit your question and we'll get our esteemed panel of experts to answer it for you.