A Criterion for the Anisotropy Barrier in Single-Molecule Magnets

Abstract

A criterion for the height of the anisotropy barrier Delta=|D|S2 in single-molecule magnets, and therefore the blocking temperature TB proportional to Delta, is presented. In particular, it is found that the anisotropy barrier does not increase with S as S2 but as S0. Consequences concerning the strategies to enhance Delta or TB, respectively, are discussed.