Influence of intermolecular interactions on magnetic observables

Very often it is an implied paradigm of molecular magnetism that magnetic molecules in a crystal interact so weakly that measurements of dc magnetic observables reflect ensemble properties of single molecules. But the number of cases where the assumption of virtually non-interacting molecules does not hold grows steadily. A deviation from the non-interacting case can especially clearly be seen in clusters with antiferromagnetic couplings, where steps of the low-temperature magnetization curve are smeared out with increasing intermolecular interaction. In this investigation we demonstrate with examples in one-, two, and three space dimensions how intermolecular interactions influence typical magnetic observables such as magnetization, susceptibility and specific heat.