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FR7_Switchable Molecules and Materials Group _Guillaume Chastanet

Guillaume Chastanet

+33(0) 5 40 00 83 23

Group description


For more than 25 years, the group has gathered together chemists, physical-chemists and physicists around photo-, piezo- and / or thermo-switchable molecular materials. This research activity fits into the general context of the development of new materials for information processing devices, pigments and sensors.

Our research themes concern multifunctional materials (photo-, piezo, thermo-commutation), materials science (optimization of properties by shaping) and molecular nanoscience (data processing, sensors). We imagine, conceive, characterize, understand, optimize and develop new molecular materials exhibiting switchable properties under external stimulation (temperature, light, pressure, current…).

The most important originality of the molecular materials that are developed and studied by the group, lies in their bistable nature, namely the presence of two different electronic states, depending on external stimulation such as pressure, temperature and / or light irradiation. Switching between these states, associated with the phenomenon of spin crossover (SCO) and/or electron transfer (ET), is accompanied by significant modifications of their mechanical, structural, dielectric, magnetic, optical and thermal properties. In addition, these modifications can be accompanied by a memory effect that in some cases can happen at room temperature, which is of high interest for data processing in solid-state devices.

Our activity is based on a proven expertise in molecular chemistry for the design and synthesis of new architectures with original, controlled and optimized properties. Our recognition in the field of photomagnetism, in close connection with an expertise in crystallography, is based on rigorous characterizations of the switching properties, leading us to a fine understanding of the structure-properties relationships at different scales of the material. Particular attention has been paid to the shaping of molecular materials (nanoparticles, molecular ceramics, thin films, etc.), particularly for issues related to charge transport in molecular nanodevices. We recently focus our attention towards the use of such switchable compounds into barocaloric devices for refrigeration devices.


  • Molecular switches
  • Spin crossover
  • Electrical transport
  • Structure-properties relationship
  • Superconductors
  • Chirality
  • Nanoparticles
  • Thin films
  • Photoswitching
  • Devices

Team Description

  • Guillaume Chastanet (Principal Investigator)

    ORCID: 0000-0001-6829-4066

  • Nathalie Daro (Research staff)

    ORCID: 0000-0002-3707-9686

  • Dominique Denux (Research staff)

  • Cédric Desplanches (Co-Principal Investigator)

    ORCID: 0000-0001-8524-3690

  • Mathieu Gonidec (Co-Principal Investigator)

    ORCID: 0000-0002-0187-1305

  • Philippe Guionneau (Co-Principal Investigator)

    ORCID: 0000-0003-4693-7715

  • Elisabeth Hillard (Co-Principal Investigator)

    ORCID: 0000-0002-5149-0324

  • Mathieu Marchivie (Co-Principal Investigator)

    ORCID: 0000-0003-1362-0797

  • François Riobé (Co-Principal Investigator)

    ORCID: 0000-0001-6746-8132

  • Patrick Rosa (Co-Principal Investigator)

    ORCID: 0000-0001-5670-2624

  • Baptiste Vignolle (Co-Principal Investigator)

    ORCID: 0000-0001-8775-1701

  • Anaïs Marchetti (Research staff)

  • Elen Duverger-Nedellec (Post-Doctoral Researcher)


  • MaChiNaCo

    Pl: E. Hillard

    Funding Agency*: National

    Ongoing: yes

  • FlowSwitch

    Pl: G. Chastanet

    Funding Agency*: National

    Ongoing: yes

  • Ximtex

    Pl: E. Hillard

    Funding Agency*: National

    Ongoing: yes

  • CNRS-Imperial College

    Pl: P. Rosa

    Funding Agency*: International

    Ongoing: yes

  • Nickel

    Pl: B. Vignolle

    Funding Agency*: National

    Ongoing: yes

* INT - International EU - European NAT - National RE - Regional


  • Atzori M., Ludowieg H., Valentín-Pérez Á., Cortijo M., Breslavetz I., Paillot K., Rosa P., Train C., Autschbach J., Hillard E. A., Rikken G., = Validation of microscopic magnetochiral dichroism theory, Science Advances, 2021

  • Poggini L., Gonidec M., González-Estefan J. H., Pecastaing G., Gobaut B., Rosa P., = Vertical tunnel junction embedding a spin crossover molecular film, Advanced Electronic Materials, 2021

  • Reeves M. G., Tailleur É., Wood P. A., Marchivie M., Chastanet G., Guionneau P., Parsons S., = Mapping the cooperativity pathways in spin crossover complexes, Chemical Science, 2021

  • Palluel M., Tran N. M., Daro N., Buffière S., Mornet S., Freysz É., Chastanet G., = The interplay between surface plasmon resonance and switching properties in gold@spin crossover nanocomposites., Advanced Functional Materials, 2020

  • Frachet M., Benhabib S., Vinograd I., Wu S.-F., Vignolle B., Mayaffre H., Krämer S., Kurosawa T., Momono N., Oda M., Chang J., Proust C., Julien M.-H. and Le Boeuf D., = High magnetic field ultrasound study of spin freezing in La1.88Sr0.12CuO, Physical Review B: Condensed Matter and Materials Physics, 2021

Research Lines


Multifunctional structures

  • Elaboration and characterization of multifunctional (switchable, chiral, plasmonic…) architectures such as molecular ceramics, nanoparticles or thin films for molecular electronic devices.

Molecular engineering

  • We use molecular engineering to design molecules, supramolecular architectures and coordination polymers that exhibit optimized switchable properties.


Unconventional molecular superconductors

  • Study of unconventional molecular superconductors – including chiral building blocks – whose electronic properties can be fine-tuned through subtle changes in the molecules at play.

Barocaloric Refrigeration Devices

  • We study macroscopic materials with strong entropy changes, and are looking for a proof-of-concept of the use of composites made of such materials for barocaloric refrigeration devices.

Cross-border Collaboration (if any)

The group has been in discussions for a few years with Prof. Luis Hueso, director of the Nanodevices Group at CIC  nanogune and professor at the UPV-EHU. Prof. Hueso is an expert in advanced nandoevices with a broad range of interests including molecular spintronics and superconductors. Our recent exchanges (about using our spin crossover compounds as magnetic impurities in spin hall devices) are but an illustration of the clear mutual interests along those research directions between our two groups, and the only thing missing for developing fruitful bilateral collaborations at this point is a dedicated funding source. We will definitely be looking forward to strengthening that partnership in the near future as well as developing new ones.

The group has also an ongoing collaboration with BCMaterials - Basque Center for Materials, Applications and Nanostructures, where Dr. I. Oyarzabal is currently working as an Ikerbasque Research Fellow. The phd student is co-supervised by Dr Oyarzabal and Dr Gonidec.