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Q & A: Does heat and coldness affect a magnet

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Most recent answer: 01/25/2018
Q:
Does heat and coldness affect a magnet and how
- Nathan (age 38)
Okc,ok
A:

I assume that you are asking about permanent (e.g., iron) magnets.  Each atom of iron is a tiny magnet.  The large iron object is magnetized when the atoms tend to align, so that the effects of the atoms add up, not cancel.  The more alignment, the stronger the magnet.  Note that there is a maximum strength, whoch occurs when all atoms are perfectly aligned.

High temperature is the enemy of order.  The hotter the object, the more the atoms jiggle around and tend to lose their alignment.  Permanent magnets lose their magnetization above a temperature called the "Curie temperature", named after Pierre Curie (Marie's husband).

Note: Any disturbance, such as dropping on the floor, will reduce the atomic alignment and weaken the magnet. Some materials are much more sensitive to this.


(published on 01/25/2018)

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