Origin of weak magnetism in compounds with cubic laves structure

The origin of the weak itinerant magnetism in materials such as TiBe₂ and ZrZn₂ is investigated. The huge peak in the density of states at the Fermi energy is attributed to a special symmetry of the C15 structure: no crystal field splitting of the d levels occurs in the case of coordination by spherical ligands. Crystal field splitting is also investigated for the f orbitals in C15 structures such as PuZn₂ and ThMg₂. It is observed that the situation in f levels is more complicated than the d levels because the characteristics of the crystal field splitting for f levels does not only depend on the the local point symmetry of the compounds. (paper)