Ask

677 readers

78 users here now

Rules

Be nice
Posts must be legitimate questions (no rage bait or sea lioning)
No spam
NSFW allowed if tagged
No politics
For support questions, please go to !newtolemmy@lemmy.ca

Icon by Hilmy Abiyyu A.

founded 2 months ago

MODERATORS

BoozeOrWater@lemm.ee

fxomt@lemmy.dbzer0.com

asudox@lemmy.asudox.dev

BoozeOrWater@lemmy.dbzer0.com

What's a really specific problem you have? (lemm.ee)

submitted 1 week ago by Irelephant@lemm.ee to c/ask@lemm.ee

42 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] zero_spelled_with_an_ecks@programming.dev 6 points 1 week ago (3 children)

The magnet sheets I cut out the use on the bottom of some tabletop miniatures sat in a sunbeam and the heat was enough to demagnetize them. So now I have to remove the magnet part that's been super glued on, replace them, and keep them out of the sun. The magnets are to keep them stuck to a ferrous tray in a storage case.

[–] shalafi@lemmy.world 1 points 6 days ago

LOL, learned the same trying to solder magnets. Yeah, turns out heat death is a thing.

[–] Drusas@fedia.io 4 points 1 week ago (3 children)

Interesting. I had no idea that UV rays demagnetize magnets.

[–] threelonmusketeers@sh.itjust.works 6 points 6 days ago

UV rays demagnetize magnets

It's the heat, not the UV: https://en.wikipedia.org/wiki/Curie_temperature

[–] thepreciousboar@lemm.ee 5 points 6 days ago (2 children)

Ferromagnetism (permanent magnetism in iron and iron alloys) happens when iron atoms (that are small magnets themselves) align to sum their magnetic fields and form a strong one we can experience in the macroscopic world.

When the magnet is heated, atoms are more energetic and more free to move around, they misalign because each atom is repelled by the others (equal poles repel each other, so when aligned they are in a constant state of repulsion, but if the material is cold they are "locked in") and the magnetic field disappears.

[–] threelonmusketeers@sh.itjust.works 1 points 3 days ago (1 children)

they misalign because each atom is repelled by the others (equal poles repel each other, so when aligned they are in a constant state of repulsion

I'm not sure this is true. When aligned, aren't all the domains lined up north to south, which would be a state of attraction?

[–] thepreciousboar@lemm.ee 1 points 2 days ago

There's still atom-to-arom repulsion because of electron shells (that are negatovely charged) and attraction because of electron pairs forming a crystal bond, and other factors I don't know about.

My explaination is a gross oversimplification, and crystal chemistry is hard, but it should give a hint of what is going on.

[–] Drusas@fedia.io 1 points 6 days ago

Thank you for the explanation!

[–] zero_spelled_with_an_ecks@programming.dev 5 points 1 week ago

I think it's just the heat itself. Seems to be what a lot of magnet sites say like https://jdamagnet.com/demagnetization-of-permanent-magnet/

[–] MutilationWave@lemmy.dbzer0.com 3 points 1 week ago (1 children)

Could you use a magnetizer instead of removing and replacing the metal?

[–] zero_spelled_with_an_ecks@programming.dev 3 points 1 week ago

Maybe! I'll have to check into how it all works.