Understanding Nanoscale Magnetization Dynamics via High-Field EPR

Molecules that exhibit slow magnetic relaxation upon removal from a polarizing magnetic field are referred to as single-molecule magnets (SMMs). SMMs receive considerable attention owing to their potential utility in applications such as spin-based information storage. In these systems, the slow relaxation normally arises from the action of an easy-axis magnetic anisotropy, quantified by a negative axial zero-field splitting parameter, D < 0, on a high-spin ground state. Two separate EPR studies carried out in the DC field facility by users from UC Berkeley (chemistry) have identified compounds that undergo slow relaxation, even though the relevant magnetic ions possess easy-plane-type anisotropy (i.e. D > 0).