Séminaire IM2NP - Amandine BELLEC - Jeudi 05 février 2026 à 15h00
Invitation : Christian Loppacher (Département PHANO, Equipe NANO).
SEMINAIRE Jeudi 05 février 2026 à 15h00
Salle des séminaires de l'Im2np, campus de Saint-Jérôme, 1er étage Bâtiment Poincaré
Amandine BELLEC
Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques (MPQ) UMR7162, F-75013, Paris.
E-mail: amandine.bellec@u-paris.fr
Control of spin-crossover molecules/metallic interface: role of the substrate
Spin-crossover molecules show the unique ability to switch between two spin-states by means of external stimuli such as temperature, light or voltage. Controlling such switches at the molecular scale and in direct contact with an electrode would be of great interest for the development of molecular devices in electronics and spintronics.
We focus our recent studies on FeII pyrazolyl borate molecules (FeMPz) adsorbed on metallic substrates such as Au(111) and Cu(111). Once absorbed, FeMPz molecules self-assembled in a 2D lattice in which both spin states can coexist at low temperature1,2. Here, we will present how the thermal induced transition from one spin state to the other evolves as a function of the molecular layer thickness (from sub-monolayer to few monolayers) when the film is grown on Cu(111)3. Then, we will discuss the recent results obtained on Cu(110), using x-ray absorption spectroscopy and grazing-incidence x-ray diffraction, that demonstrate that not only the nature of the substrate but also its symmetry is an important parameter to take into account. Finally, we will show how the spin transition can be induced by voltage-pulses at the molecular level4.
Figure 1. a) Scheme of the manipulation by voltage-pulses. b) 10 x 10nm2 and c) 10 x 12.5nm2 topographic images where “LS” and “HS” have been written by voltage pulses (V = 0.3 V, I = 3 pA).
References
1 K. Bairagi et al., Nat. Comm., 2016, 7, 12212.
2 C. Fourmental et al., J. Phys. Chem. Lett., 2019, 10, 4103.
3 M. Kelai et al. J. Phys. Chem. Lett., 2021, 12, 6152-6158.
4 Y. Tong et al., J. Phys. Chem. Lett, 2021, 12, 11029-11034.
