Impact of the spin state switching on the dielectric constant of iron (II) spin crossover nanoparticles

- Spin state nanoparticles of spin state compounds can be easily prepared in solution, but it is very difficult to isolate such nanoparticles.
- When the temperature of the solution increases, the nanoparticles switch from a low spin state to the high spin state and the solution, initially pink, becomes transparent.
- We propose a simple technique which makes it possible to determine specifically the index of refraction and absorption coefficient of the nanoparticles in the visible spectral range.
- This technique is used to retrieve the change of these parameters during a spin state transition taking place in the solution.