Re‐Appearance of Cooperativity in Ultra‐Small Spin‐Crossover [Fe(pz){Ni(CN)4}] Nanoparticles |
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| Authors: | Haonan Peng Dr Simon Tricard Gautier Félix Dr Gábor Molnár Dr William Nicolazzi Dr Lionel Salmon Dr Azzedine Bousseksou |
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| Institution: | 1. Laboratoire de Chimie de Coordination, CNRS UPR‐8241 and Université de Toulouse;2. UPS, INP, 31077 Toulouse (France) |
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| Abstract: | A reverse nanoemulsion technique was used for the elaboration of Fe(pz){Ni(CN)4}] nanoparticles. Low‐temperature micellar exchange made it possible to elaborate ultra‐small nanoparticles with sizes down to 2 nm. When decreasing the size of the particles from 110 to 12 nm the spin transition shifts to lower temperatures, becomes gradual, and the hysteresis shrinks. On the other hand, a re‐opening of the hysteresis was observed for smaller (2 nm) particles. A detailed 57Fe Mössbauer spectroscopy analysis was used to correlate this unusual phenomenon to the modification of the stiffness of the nanoparticles thanks to the determination of their Debye temperature. |
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| Keywords: | Debye temperature Mö ssbauer spectroscopy nanoparticles spin crossover transition metals |
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