INDUCING SPONTANEOUS MAGNETIZATION IN ANTIFERROMAGNETS

Spontaneous magnetization is a most important property in magnetism be cause of both practical and fundamental reasons, However, nature tends to favour antiferromagnetic alignment better than ferromagnetic one. This is particularly so in the case of molecular systems, This paper e mphasizes the point that such tendency does not necessarily excludes t he possibility of the presence of spontaneous magnetization in systems where antiferromagnetic interactions dominate and reviews several pos sibilities other than the well-known ferrimagnetism that permit induci ng spontaneous magnetization in antiferromagnets Examples include favo uring non collinear antiparallel alignment of the magnetic moments, or the flipping of spins to parallel alignment by the action of a small magnetic field, The introduction of a certain degree of magnetic disor der in antiferromagnetic lattices can also produce a remnant magnetiza tion in the material. Necessary conditions required for each strategy and some selected examples are discussed.