The Neel temperature, T N, is the temperature at which an antiferromagnetic material becomes paramagnetic - that is, the thermal energy becomes large enough to upset the magnetic ordering within the material.
The Neel temperature is analogous to the Curie temperature, T C, for ferromagnetic materials. It is named after Louis Néel (1904-2000), who received the 1970 Nobel prize in physics for his work in the area.
