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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Interface versus Bulk Light-Induced Switching in Spin-Crossover Molecular Ultrathin Films Adsorbed on a Metallic
Massine Kelai1, Arthur Tauzin2, Anastasia Railean3
1Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques, F-75013 Paris, France.
Abstract:
Spin-crossover molecules present the unique property of having two spin states that can be controlled by light excitation at low temperature. Here, we report on the photoexcitation of [FeII((3, 5-(CH3)2Pz)3BH)2] (Pz = pyrazolyl) ultrathin films, with thicknesses ranging from 0.9 to 5.3 monolayers, adsorbed on Cu(111) substrate. Using X-ray absorption spectroscopy measurements, we confirm the anomalous light-induced spin-state switching observed for sub-monolayer coverage and demonstrate that it is confined to the first molecular layer in contact with the metallic substrate. For higher coverages, the well-known light-induced excited spin-state trapping effect is recovered. Combining continuous light excitation with thermal cycling, we demonstrate that at low temperature light-induced thermal hysteresis is measured for the thicker films, while for sub-monolayer coverage, the light enables extension of the thermal conversion over a large temperature range. Mechanoelastic simulations underline that, due to the intermolecular interactions, opposite behaviors are observed in the different layers composing the films.
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