Transformation of Antiferromagnetic Type of Exchange Interaction into Ferromagnetic One in Dimer Clusters

Abstract

We consider coordination compounds of ions with unfilled up 3d- and 4f-shell in a weak or intermediary crystalline field, containing dimer clusters in the case when the distance between clusters is more than the distance between the ions forming the cluster. In this case it is possible to neglect the exchange interaction between electrons of different clusters and the structure of the ground state of separate dimer is determined by the intercluster exchange, spin orbital, magnetic dipole–dipole, and hyperfine interactions. The presence of other dimers in the crystal is possible to take into account if populations of energy levels of system upon interacting dimer clusters are calculated.