Geometry-Mediated Enhancement of Single-Ion Anisotropy: A Route to Single-Molecule Magnets with a High Blocking Temperature

摘要

Gaising the blocking temperature (T_b) of magnetization reversal in single-molecule magnets (SMMs) is a formidable challenge that has to be addressed for their eventual practical application. A SMM displaying characteristic freezing of magnetization along a preferred direction in the absence of external magnetic field at above approximately 14 K has been elusive so far. Tremendous efforts are being devoted to rationalize the parameters governing the energy barrier of magnetization reversal (U) in SMMs. The thermal energy barrier of magnetization reversal between ground ± Ms levels is related to the axial zero-field splitting D and ground-state spin S through the expression U = S~2 |D| (or U=(S~2-I/4) | D | for non-integer spins; Figure 1).