Tracking the photoswitching dynamics of bistable spincrossover molecules at solid state
Résumé
In this work we demonstrate by combining ultrafast optical and X-ray diffraction techniques, the spin state switching of a Fe(III) spin-crossover solid triggered by a femtosecond laser flash, and show that different processes on different length and time scales are involved. The dynamics span from sub-picosecond non-thermal local molecular photoswitching to slower unit cell volume expansion (nanosecond) to diffusive heating processes through the lattice (microsecond). The results contribute to the understanding of different consecutive processes on different length and time scales following a localized electronic excitation of molecules in the solid.