2. Classification of Magnetic media磁介质的分类 Based on the relation between B and b, the matter can be divided into three kinds: →(1) Paramagnetic substance(顺磁质):B'has same direction of B, that is B>b; (2) Diamagnetic substance(抗磁质):Bis matter opposite to Bo, that is B<Bo; 3) Ferromagnetic substance(铁磁质):Bhas the same direction of b. and B>>b2.Classification of Magnetic Media 磁介质的分类 Based on the relation between and , the matter can be divided into three kinds: B  B  matter (1)Paramagnetic substance(顺磁质 ): has same direction of , that is ; B  B   B  B (2) Diamagnetic substance(抗磁质）： is opposite to , that is ; B  B0  B B0  (3)Ferromagnetic substance(铁磁质): has the same direction of and ; B  B0   B  B