Magnetic Ordering in the Ferromagnetic Rare-Earth Metals

Abstract

The ferromagnetic rare-earth metals show the magnetic transition from the ferromagnetic state to the antiferromagnetic state. The possibility of this kind of magnetic transition between spin arrangements is discussed on the basis of the spin wave approximation. It is shown that the transition from the ferromagnetic to the helical spin arrangement which has recently been observed in dysprosium and holmium can occur when a large axial anisotropy field exists. The temperature dependence and the field dependence of the pitch of the helical structure are calculated on the same standpoint of the spin wave theory.