Spin crossover nano(hybrid)particles: from synthesis to time-resolved characterization of individual particle by ultrafast transmission electron microscopy
Résumé
There are many phenomena that can be used to store data, such as the change in electronic configuration in the so-called spin crossover materials (SCO) that is associated to volume change (up to 10%). These can be miniaturized in nanoparticles, in particular for their integration into opto- electronic [1], while maintaining a crucial memory effect to store information, especially by light. This photo-inscription requires high irradiation energies. It is the heat deposited by the irradiation that induces a local heating effect and allows the switching at room temperature. In this work, we wanted to reduce the irradiation energy required for this photothermal effect, by introducing gold nanorods (70x25 nm) into switchable particles to create Au@SCO nanohybrids (200x100 nm). Excitation of the plasmon resonance of these gold particles amplifies the local heating effect. This strategy reduced the irradiation power by a factor of 10 000 compare to the literature [2]. Energy and photoswitching gain time were studied by timeresolved optical measurements as well as by ultrafast single-particle transmission electron microscopy (UTEM) by probing the size change of an individual particle under a few nanosecond laser pulse [3,4].
Domaines
Matériaux| Origine | Fichiers produits par l'(les) auteur(s) |
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