Rules for Understanding and Designing Novel Molecular-Based Rare-Earth Magnetic Compounds

摘要

Results of SDFT calculations were used to construct and check features of a generally applicable qualitative approach to understanding magnetic coupling in rare-earth-rich compounds.Using fragments based on structures of metal-rich lanthanide compounds,we have investigated molecular and low-dimensional extended structures,including Gd_3I_6(OPH_3)_12,Gd_6I_12Co(OPH_3)_6,and Gd_2Cl_3.Open-d-shell clusters facilitate strong ferromagnetic coupling whereas in the closed-d-shell systems prefer antiferromagnetic coupling.The f-d exchange interaction,mediated by spin polarization of both filled and partially-filled metal-metal bonding orbitals,was described for the model system Gd_3i_6(oph_3)_12~(n+) using basic perturbation methods.This method has been successful for predicting the magnetic ground state for models of Gd[Gd_6I_12Fe] and Gd_2Cl_3.