Is neodymium naturally magnetic?

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    Magnetic Neodymium
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Discussion Overview

The discussion revolves around the magnetic properties of neodymium, particularly whether it is naturally magnetic and its suitability as a core material for electromagnets compared to iron. Participants explore the conditions under which neodymium exhibits magnetism and its practical applications in magnet manufacturing.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that neodymium is ferromagnetic but only exhibits magnetism at extremely low temperatures (19 K), and its natural state does not allow it to be used as a metal without refinement.
  • It is mentioned that neodymium magnets are typically made from compounds of neodymium with iron and boron, which have higher Curie temperatures suitable for practical use.
  • Concerns are raised about neodymium's rapid oxidation, toxicity, and flammability at relatively low temperatures, suggesting it may not be an ideal core material for electromagnets compared to iron.
  • Participants discuss the necessity of encasing neodymium magnets in nickel to protect them from oxidation, with personal anecdotes about the durability of such magnets.

Areas of Agreement / Disagreement

There is no consensus on whether neodymium is a better core material for electromagnets than iron, as participants present differing views on its properties and practical applications.

Contextual Notes

Participants highlight that neodymium does not occur naturally as a metal and must be refined from ores, which may affect its availability and application in various contexts.

kolleamm
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Also does it make a better core for an electromagnet than iron does?
 
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kolleamm said:
Also does it make a better core for an electromagnet than iron does?
from wiki

Neodymium is a metal which is ferromagnetic (more specifically it shows antiferromagnetic properties), meaning that like iron it can be magnetized to become a magnet, but its Curie temperature (the temperature above which its ferromagnetism disappears) is 19 K (−254 °C), so in pure form its magnetism only appears at extremely low temperatures.[5] However, compounds of neodymium with transition metals such as iron can have Curie temperatures well above room temperature, and these are used to make neodymium magnets.

note it is only naturally magnetic at extremely low temperatures
This is why Nd magnets are a mix of Nd Fe ( Iron) and B (Boron)
Also note that Nd does not occur naturally as a metal, it needs to be refined out of the ores that it is present in

and to answer your specific Q ...
Also does it make a better core for an electromagnet than iron does?

no, it oxidises VERY quickly, even when mixed with iron and boron
it's also toxic and flammable at temps as low as 150C
Dave

edited to fix spelling and grammar
 
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davenn said:
from wiki
note it is only naturally magnetic at extremely low temperatures
This is why Nd magnets are a mix of Nd Fe ( Iron) and B (Boron)
Also note that Nd does not occur naturally as a metal, it needs to be refined out of the ores that it is present in

and to answer your specific Q ...no, it oxidises VERY quickly, even when mixed with iron and boron
it's also toxic and flammable at temps as low as 150C
Dave

edited to fix spelling and grammar
Thanks a lot! That pretty much sums it all up.
 
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davenn said:
no, [neodymiun] oxidises VERY quickly, even when mixed with iron and boron
it's also toxic and flammable at temps as low as 150C.
Hmm, now I understand why these very strong permanent magnets have to be encased in nickel.

(I bought one some years ago and it still seems to be as strong as ever.)
 
strangerep said:
Hmm, now I understand why these very strong permanent magnets have to be encased in nickel.
Yup, I have a cylindrical one here (1/2 " dia. 1" long) that a little of the nickel plating has peeled off and the Nd mix below is oxidising nicely

D
 

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