Optical imaging of the stochastic nucleation kinetics and intrinsic activation energy of single Spin-crossover nanoparticles

While bistable spin crossover materials with wide hysteresis represent promising applications for molecular memory devices, little has been assessed regarding their intrinsic spin transition kinetics and activation energy barriers due to the lack of suitable techniques. The developed thermal-optical methodology demonstrates the capability to quantify these important kinetic and thermodynamic properties of single spin-crossover nanoparticles. It not only provides the first experimental evidence of the stochastic nucleation behavior during repeatable spin transitions, but also identifies a minority with extraordinary performance taking advantage of the high throughput of the developed methodology. Combined with the in-situ regulations, the results reveal the intrinsic high activation energy of ideal SCO crystals and thus promise a prolonged lifetime of their bistable states.