Magnetic Anisotropy and Spin-Parity Effect Along the Series of Lanthanide Complexes with DOTA

摘要

Magnetic anisotropy, arising from the unquenched orbital contribution of the partially occupied inner 4forbitals combined with the crystal field that breaks the spherical symmetry, is the key property that makes lanthanides a unique ingredient in magnetism. Molecular magnetism makes no exception, especially in the field of bistable materials, like single-molecule magnets (SMM) and single-chain magnets (SCM). In the first case the magnetic anisotropy generates a barrier for the reversal of the magnetization of the molecule that can be overcome either by thermal activation, leading to an exponential growth of the relaxation time at low temperature, or by underbarrier mechanisms, which are severely affected by the symmetry of the crystal field and by the application of an external magnetic field.