In physics and material science  , the Curie temperature ( T _C ), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties, which can (in most cases) be replaced by induced magnetism . The Curie temperature is named after Piere Curie  , who showed that magnetism was lost at a critical temperature.

The force of magnetism is determined by the magnetic moment  a dipole moment within an atom which originates from the angular momentum and spin of electrons. Materials have different structures of intrinsic magnetic moments that depend on temperature; the Curie temperature is the critical point at which a material's intrinsic magnetic moments change direction.

Permanent magnetism is caused by the alignment of magnetic moments and induced magnetism is created when disordered magnetic moments are forced to align in an applied magnetic field. For example, the ordered magnetic moments ( ferromagnetic  change and become disordered  at the Curie temperature. Higher temperatures make magnets weaker, as spontaneous magnetism only occurs below the Curie temperature. Magnetic susceptibility  above the Curie temperature can be calculated from the Curie–Weiss law  , which is derived from Curie's law

In analogy to ferromagnetic and paramagnetic materials, the Curie temperature can also be used to describe the phase transition between ferroelectricity  and paraelectricity  . In this context, the order parameter  is the electric polarization that goes from a finite value to zero when the temperature is increased above the Curie temperature.

Hello Tanu!

For a ferromagnetic material, Curie temperature or Curie point (T _C ) is the critical temperature above which the material becomes paramagnetic. For iron the Curie point is 760 °C and for nickel 356 °C. It was named after the French physicist Pierre Curie (1859-1906).

Hope this will help you!!