Science Buddies: "Ask an Expert"

I'm doing an investigation to test how magnetic field strength varies with temperature using a neodymium magnet. My goal is to find the curie temperature of the magnet by extrapolating the data.

Should I expect a linear relationship between these variables? Also, I know that the curie temperature is the point at which a magnet becomes paramagnetic (only has induced magnetism) but does this also imply that the magnetic field strength should be zero?

I've tried to find these answers online but am finding a lot of different theories which I cannot confirm. Any help answering these questions would be very much appreciated.

Hi,

I'm assuming that you're working on the project described here:

viewtopic.php?f=29&t=19614

The following link includes an equation that approximates the temperature effect on magnetic moment for temperatures below the Curie point.

https://en.wikipedia.org/wiki/Curie_temperature

This equation indicates that the relationship between temperature and magnetic moment is not linear. You might try using this equation for your extrapolation, then compare your Curie point with published values. You should find Curie temperatures for the different types of neodymium magnets in an online search.

At the Curie temperature, the ferromagnetic property disappears. This means that the material no longer has a magnetic field. But the material can be magnetic in the presence of a magnetic field (paramagnetic).

You might be interested in the information here:

http://hyperphysics.phy-astr.gsu.edu/hb ... ro.html#c3

I hope this helps. Please ask again if you have more questions.

A. Norman