In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature where a material’s permanent magnetism changes to induced magnetism. The force of magnetism is determined by magnetic moments.

The Curie temperature is the critical point where a material’s intrinsic magnetic moments change direction.

 

 

 

 

Figure 1 Below the Curie temperature, neighbouring magnetic spins align in a ferromagnet in the absence of an applied magnetic field.

 

 

 

 

 

Figure 2 Above the Curie temperature, the magnetic spins are randomly aligned in a paramagnet unless a magnetic field is applied.

Sources:

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