The temperature above which an antiferromagnetic substance becomes paramagnetic (see magnetism). The susceptibility increases with temperature, reaching a maximum at the Néel temperature, after which it abruptly declines. The realization that in an antiferromagnet there is a temperature analogous to the Curie point of a ferromagnet is owing to Louis Néel (1904–2000), who described the magnetic behaviour of antiferromagnets in 1936.