Study of the fast photoswitching of spin crossover nanoparticles outside and inside their thermal hysteresis loop

Geoffrey Gallé (1) , Céline Etrillard (2) , Jérôme Degert (1) , François Guillaume (3) , Jean-François Létard (2) , Eric Freysz (1)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 ISM - Institut des Sciences Moléculaires

We have studied the low spin to high spin phase transition induced by nanosecond laser pulses outside and within the thermal hysteresis loop of the [Fe(Htrz)2 trz](BF4)2-H2O spin crossover nanoparticles. We demonstrate that, whatever the temperature of the compound, the photo-switching is achieved in less than 12.5 ns. Outside the hysteresis loop, the photo-induced high spin state remains up to 100 μs and then relaxes. Within the thermal hysteresis loop, the photo-induced high spin state remains as long as the temperature of the sample is kept within the thermal loop. A Raman study indicates that the photo-switching can be completed using single laser pulse excitation.

Domaines: Optique [physics.optics]

Geoffrey Gallé, Céline Etrillard, Jérôme Degert, François Guillaume, Jean-François Létard, et al.. Study of the fast photoswitching of spin crossover nanoparticles outside and inside their thermal hysteresis loop. Applied Physics Letters, 2013, 102 (6), pp.063302 (1-4). ⟨10.1063/1.4792527⟩. ⟨hal-00795299⟩