Description du projet
Des aimants monomoléculaires à des températures sans précédent
Les aimants monomoléculaires (SMM) sont une classe de matériaux composés de molécules individuelles qui affichent un comportement magnétique au niveau moléculaire. Les SMM présentent la capacité unique d’hystérèse magnétique, ce qui signifie qu’ils peuvent conserver leur magnétisation même en l’absence d’un champ magnétique externe. Cette propriété fait des SMM un candidat prometteur pour des applications potentielles dans des dispositifs à l’échelle nanométrique. Financé par le Conseil européen de la recherche, le projet RadMag entend créer des SMM innovants pouvant fonctionner à des températures plus élevées en combinant de nouveaux ligands radicaux. La réussite du projet pourrait révolutionner le domaine des SMM et ouvrir la voie à des applications pratiques à des températures plus élevées.
Objectif
Single-molecule magnets (SMMs) display magnetic hysteresis that is molecular in origin, and these materials have huge potential to be developed as nano-scale devices. The big challenge is to create SMMs that function without the need for liquid-helium cooling.
This project will develop new SMMs that combine the strong magnetic anisotropy of lanthanide ions with a series of novel radical ligands. Our innovative SMMs will have controllable molecular and electronic structures, which will ultimately enable hysteresis at unprecedented temperatures.
Highly unusual di- and tri-metallic Ln-SMMs are proposed in which the metals are bridged by radicals with heavy Group 15 (phosphorus-bismuth) and Group 16 (sulphur-tellurium) donor atoms. Trimetallic SMMs will also be based on hexaazatriphenylene (HAT) radicals, and dimetallic SMMs will also be based on nindigo radicals, both of which are nitrogen-donor ligands.
The SMM field is dominated by systems with diamagnetic ligands. Our radical ligands have never been used in SMM studies: their diffuse unpaired spin provides a way of switching off the quantum tunnelling mechanisms that otherwise prevent hysteresis. We will exploit the rich electrochemistry of the target ligands: heavy p-block radicals have huge spin densities on the donor atoms; HAT radicals can have up to three unpaired electrons; reduced or oxidized nindigo radicals allow access to redox-switchable SMMs. In the HAT-bridged SMMs, the use of ligands with more than one unpaired electron is unprecedented. The heavy p-block ligands are themselves are novel.
The PI’s approach to SMMs has already established new directions in lanthanide chemistry and in molecular magnetism. He now proposes a new, radical approach to SMMs with potential to re-define the state of the art, and to extend the frontiers of a vibrant multi-disciplinary field. Achieving the aims will provide a major step towards using SMMs for applications at practical temperatures.
Champ scientifique
Mots‑clés
Programme(s)
Régime de financement
ERC-COG - Consolidator GrantInstitution d’accueil
BN1 9RH Brighton
Royaume-Uni