Magnetic cluster excitations

Magnetic cluster systems can be considered as nanomagnets consisting of a small number of interacting spins that are magnetically isolated from the neighboring clusters of the compound by nonmagnetic ligands. Inelastic neutron scattering is a powerful experimental tool for the study of magnetic clusters, since it provides direct access to energy splittings. The present work presents the underlying concepts, which are illustrated for some representative examples such as single-molecule magnets, diluted magnets and magnetic polarons. It is shown that - besides the dominant Heisenberg interaction - higher-order exchange terms are often needed to rationalize the experimental data.