01-18U

A comparative analysis of the different actinide compounds [metals, intermetallic compounds (heavy fermion systems, Kondo lattices, mixed valence systems) and dielectrics] with respect to the formation of the magnetic moments, effective interactions and magnetic properties is performed. It is stressed that the strong influence of the environment (crystal electric field splitting, $sd$-$f$ hybridization) leads to the strong spin-phonon interaction and sensitivity of the magnetic properties of the actinide compounds to the structure (crystal lattice type, local environment, defects) and different excitations (phonons, excitons, etc.).