Institut de Chimie Moléculaire et des Matériaux d'Orsay

Laboratoire de Chimie Inorganique - LCI

Supramolecular magnetic nano-objects and Surface chemistry

Victoria E. Campbell,Talal Mallah, Sandra Maszerat
Fatima El Khatib (Ph.D. candidate), Feng Shao (Ph.D. candidate), Monica Tonelli (Erasmus student), Marta Viciano (post-doc), George Zakhia (Ph.D. candidate)


 

Supramolecular magnetic nano-objects

The overreaching goal of this project is the self-assembly of metal-containing nano-objects towards the construction of spintronic devices. The project lies at the interface between inorganic chemistry, supramolecular chemistry, magnetic materials, surface science and physics. The basic question to be answered in the proposed research is: can we design supramolecular nano-objects suitable for spintronic applications?

 

Fig. 1 a) Synthesis of SMM molecules. b) MicroSQUID measurements showing hysterisis.

 

References: Stuctural and Electronic Dependence of the Single-Molecule-Magnet Behavior of Dysprosium(III) Complexes V. E. Campbell,* Hélène Bolvin, E. Riviere, R. Guillot, W. Wernsdorfer and T. Mallah* Inorg. Chem., 2014, 53, 2598-2605

Supcomponent Self-Assembly of Rare Earth Single Molecule Magnets. V. E. Campbell,* R. Guillot, E. Riviere, P.-T. Brun, W. Wernsdorfer and T. Mallah , Inorg. Chem., 2013,52, 5194-5200.

Surface chemistry

Within the general frame “Nanoscience”, we are exploring the behaviour of single molecule magnets chemically grafted onto surfaces. This approach opens the possibility to obtain well separated nanoobjects, strongly bonded to different substrates such as silicon, silicon dioxide and niobium.

 

Fig. 1 a) Synthesis of SMM molecules. b) MicroSQUID measurements showing hysterisis.

 

 

Magnetic anisotropy

The study of the magnetic anisotropy of a series of mononuclear Ni(II) pentacoordinate complexes shows that the nature and the magnitude of the anisotropy is imposed by the tertradentate ligand. High-field High Frequency Electron Paramagnetic Resonance studies together with semi-empirical theoretical calculations were used to rationalize the experimental magnetic data. Furthermore, the semi-empirical calculations were used to predict the evolution of the nature and the magnitude of the magnetic anisotropy in pentacoordinate complexes between square pyramidal and trigonal bipyramidal geometries. The important result of this work is the possibility for chemist to design complexes with predictable magnetic anisotropy by shaping the organic ligand in mononuclear complexes

 

 

 Fig. 2.Calcul théorique semi-empirique de la variation de la valeur du paramètre d’anisotropie D (D est positif pour un plan de facile aimantation et negatif pour un axe de facile aimantation) en fonction de la nature des ligands et de la géométrie de complexes de Ni(II) e coordinence 5; les résultats expérimentaux sont indiqués par une croix sur la surface obtenue.

 

Références: Large magnetic anisotropy in pentacoordinate Ni(II) complexes. J. N. Rebilly, G. Charron, E. Rivière, R. Guillot, A. L. Barra, M. D. Serrano, J. van Slageren and T. Mallah, Chem-Eur. J., 2008, 14, 1169-1177 (VIP).

 

 

 

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