Hi

How many occurrences of the following event would it take for a rare earth magnet to become [SIZE=-1]demagnetized?

the event:
2 same size and shape magnets, north of one approaching the north of the other "with out touching" and then moving away.

thx
[/SIZE]

 

There a study that the magnetic poles have reversed before
and could do it again.The study shows the earth magma in
fuild like state. Looks mercury that could just flow to opposite
side.They have demagnetised Bats that could not find there ways home
until the effect wore off. Like every thing there is doom day mention
reversing poles.

 

From - http://www.kjmagnetics.com/neomaginfo.asp

Demagnetization
Rare Earth magnets have a high resistance to demagnetization, unlike most other types of magnets. They will not lose their magnetization around other magnets or if dropped. They will however, begin to lose strength if they are heated above their maximum operating temperature, which is 176°F (80°C) for standard N grades. They will completely lose their magnetization if heated above their Curie temperature, which is 590°F (310°C) for standard N grades. Some of our magnets are of high temperature material, which can withstand higher temperatures without losing strength.

Here is a link to the mechanism that causes magnetization and demagnetization - http://www.britannica.com/EBchecked/topic/356975/magnet

 

The so-called Rare Earth magnets are hard magnets. That is, they are not easily magnetized or de-magnetized. Heat can destroy the magnet's coercive force as can disrupting the magnetic circuit path with force.

Regards, DPW