Electronic and structural factors controlling the spin orientations of magnetic ions
In discrete molecules and extended solids, magnetic ions M are surrounded with ligands L to form MLn (typically, n = 2 - 6) complexes. The spin moments of M exhibit preferential orientations with respect to the local coordinates defining the structures of MLn complexes. Elaborate experimental measurements and sophisticated first principles computational efforts are necessary to find the preferred spin orientations of magnetic ions M. However, they can be readily predicted on the basis of qualitative perturbation theory in which the spin-orbit coupling (SOC) of M is taken as the perturbation with the magnetic orbitals of MLn in the absence of SOC as the unperturbed states. This analysis gives rise to simple and powerful selection rules with which to predict the preferred spin orientations of magnetic ions M based on the minimum difference in the magnetic quantum numbers of M in the HOMO and LUMO of MLn.
- 2019 SNU Physics Whangbo.pdf (2 MB, download:13)