Historical introduction ate l9th o early 20th Properties of magnets 1895 P Curie linear T-dependence of inverse susceptibility 1905 P. Langevin Theoretical explanation of Curie law langevin diamagnetism 1907 P. Weiss molecular field theory of ferromagnetism C x T T-6 Curie law Curie-Weiss law(1907) 1928 Heisenberg model 1932-36 Neel Generalied Weiss theory for antiferromagnetsHistorical introduction Late 19th ~ early 20th Properties of magnets 1895 P. Curie Linear T-dependence of inverse susceptibility 1905 P. Langevin Theoretical explanation of Curie law & Langevin diamagnetism 1907 P. Weiss Molecular field theory of ferromagnetism 1928 Heisenberg Model 1932-36 Neel Generalied Weiss theory for antiferromagnets Curie law Curie-Weiss law (1907)