Origin of single molecule magnet behavior of a trinuclear [Ni2Dy] cluster

The manifestations of single ion anisotropy of the DyIII ion in the key physical properties of the [L2Ni2Dy][ClO4] single molecule magnet have been examined. The crystal field acting on the DyIII ion and the exchange interaction coupling the DyIII and NiII ions are included in the model. It is shown that the role of the NiII ions is only to increase the total angular momentum of the cluster via coupling through superexchange with the DyIII ion. The model describes well the observed temperature dependence of the magnetic susceptibility and the field dependence of magnetization.