Can I store a neodymium magnet in a freezer?

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    Magnet Neodymium
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Discussion Overview

The discussion revolves around the storage of neodymium magnets, specifically whether placing them in a freezer affects their magnetization. The scope includes theoretical considerations of magnet behavior at different temperatures and practical implications for storage conditions.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant explains that permanent magnets lose magnetization above the Curie temperature due to thermal energy affecting magnetic moments.
  • Another participant clarifies that the Curie Point for neodymium magnets is well above typical room temperatures, suggesting that concerns about magnetization loss at room temperature are unfounded.
  • A different participant states that storing neodymium magnets in a freezer is equivalent to room temperature in terms of magnet strength retention, noting that specific formulations of Nd magnets have varying Curie temperatures.
  • It is mentioned that magnets may shatter if subjected to rapid temperature changes, raising a caution about thermal stress.

Areas of Agreement / Disagreement

Participants express differing views on the necessity and impact of storing neodymium magnets in a freezer, with some arguing it is unnecessary while others caution about potential risks related to temperature changes.

Contextual Notes

There is a lack of consensus on the practical benefits of storing magnets at low temperatures versus room temperature, and the specific conditions under which magnetization might be affected remain unresolved.

rohit dutta
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Well, permanent magnets are made of ferromagnetic material. These magnets lose permanent magnetization above the Curie temperature(on heating) and behave as paramagnetic materials. The reason is thermal energy. The magnetic moments lose their initial configuration and no longer remain aligned with each other. This reduces it's overall strength.

Can I place my magnets in a freezer to ensure no loss in magnetization?
 
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It's not clear why you are concerned about loss of magnetization. The Curie Point, the temperature at which magnetization of a substance is lost, is well over 900 C for Nd magnets and 1000 C for iron magnets. As long as you aren't wandering around on the surface of Venus or Mercury, your magnets should be good to go at room temp.
 
Nd magnets in freezer

Yes, you can store them in a freezer. This will be no different from storing them at room temperature with respect to their losing their magnetic strength over time.

Nd:Fe:B magnets have different Curie temperatures depending on their specific formulation. The ones with the highest field strength tend to have lower Curie temperatures. If you're building systems that incorporate rare Earth magnets (at least the Nd based magnets I'm familiar with), you should ensure they don't get above 100°C for short periods (think a few minutes). A good engineering design rule is to limit them to 80°C.

Storing them in a freezer, or anywhere below normal ambient temperature, will have no benefit and probably isn't worth the effort.
 
Magnets that are brittle may shatter when subjected to rapid temperature changes.
 

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