Dynamics of Spin Crossover Molecular Complexes

We review the current understanding of the time scale and mechanisms associated with the change in spin state in transition metal-based spin crossover (SCO) molecular complexes. Most time resolved experiments, performed by optical techniques, rely on the intrinsic light-induced switching properties of this class of materials. The optically driven spin state transition can be mediated by a rich interplay of complexities including intermediate states in the spin state transition process, as well as intermolecular interactions, temperature, and strain. We emphasize here that the size reduction down to the nanoscale is essential for designing SCO systems that switch quickly as well as possibly retaining the memory of the light-driven state. We argue that SCO nano-sized systems are the key to device applications where the write speed is an important criterion.

Automated summary

The understanding of the time scale and mechanisms associated with spin state changes in transition metal-based spin crossover (SCO) molecular complexes is reviewed. Most time resolved experiments are carried out using optical techniques, revealing the complex interplay of factors influencing the optically driven spin state transition. Size reduction to the nanoscale is essential for designing SCO systems with fast switching capabilities, making nano-sized SCO systems key for device applications where write speed is crucial.