Curie's Law: In a paramagnetic material the magnetization of the material is directly proportional to an applied magnetic field. However, if the material is heated, the magnetization is inversely proportional to temperature.
i.e. M = C x ( B / T )
M is the magnetisation
B is the magnetic field, measured in teslas
T is absolute temperature, measured in kelvins
C is a material-specific Curie constant
It was first discovered experimentally by French physicist, Pierre Curie. It holds for high temperatures, or weak magnetic fields.