Jump to content

Does currie´s law work on permanent magnets?


sigven

Recommended Posts

Hey. I`m going to do an experiment to se if the magnetic field around a magnet changes when the temperature of the magnet changes.

 

According to Currie´s law, M = C x ( B / T ), the magnetization of a material is inversely proportional to the temperature.

If I have understood this right this means that f.ex. a iron nail in a magnetic field will be less magnetized if the temperature of the nail is higher. This equation does not speak of the temperature of the magnet which is making the magnetic field.

My question is: can i use the same equation to determine how the magnetic field around a permanent magnet will change as a function of the magnet´s temperature?

Link to comment
Share on other sites

Nether the nail, nor the magnet are paramagnetic, so Curie's law doesn't apply.

 

Does Curie´s law apply only to paramegnetic materials?

 

For a permanent magnet, I think you want the Curie-Weiss law: https://en.wikipedia.org/wiki/Curie%E2%80%93Weiss_law

This only applies above the Curie point where the magnet loses its ferromagnetism.

 

Is there no law that accounts for the change in magnetic field strength of a permanent magnet bellow the Currie point

Link to comment
Share on other sites

  • 1 month later...

The same material may be ferromagnetic or, above its Curie temperature, paramagnetic.

 

I doubt a simple law works for ferromagnetic materials. Theories have been tried, but in docs for permanent magnets I've never seen one mentioned, only experimental curves, so simple theories resembling a thermodynamics distribution must fail.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.