ANISOTROPY OF MAGNETISM IN ACTINIDE AND LANTHANIDE INTERMETALLICS

The magnitude of magnetic moments of 4f-electrons in lanthanide intermetallics is well understood in the single-ion picture considering a crystal field interaction which also determines the magnetocrystalline anisotropy in these materials. In intermetallic compounds of actinides, this concept fails due to a significant delocalization of 5f-electron states. Systematic occurrence of particular types of anisotropy in different type structures suggests that the type of magnetic anisotropy is related to a bonding anisotropy. A mechanism responsible for giant anisotropy energies in actinides can be found in the anisotropic bonding of 5f electrons yielding anisotropic exchange interaction between 5f magnetic moments.