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Molecular-based magnets

One of the major challenges for the years to come involves the use of the most recent breakthroughs in the field of very high-density information storage. The production of nanomaterials, such as metallic dots, clusters or aggregates organised on a surface, enable us to envision unequalled storage densities (> 1012 bits/cm2). Along with classic synthesis procedures, inverse micelle reactions have also proven to be very efficient for isolating objects with very high magnetic moments, in between that of molecules (maximum of 25 µB) and that of metallic particles (minimum of 1000 µB).

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The synthesis of molecular-based objects must enable this new stage to be attained, even if operating temperatures exclude all applications to this date. The tools and knowledge exist today to build molecular structures with high spins, nanometric in size, and with unreported magnetic properties (tunnel effect of the magnetisation of single-molecule magnets, for example. Refer to the attached figure).

If various examples of large-sized molecular species were produced, with properties governed by classical and quantum laws of physics, the spatial layout of these entities, or in other words the dimensionality of the assembly, often remains random. This last point is of utmost importance in the field of magnetism, and in the long run, mastering it will be crucial to the development of systems based on molecular magnets.
In the same way, critical temperatures that are often too low are incompatible with use as components, and a real effort will need to be made in order to foresee applications at ambient temperature. As specialised chemists work closely with small inorganic particles – even metallic – the fields of use will evolve favourably.

The following courses should be favoured by contributors to the network :

  • The synthesis of small objects through a “bottom-up” process that possesses the structural and electronic properties required to proceed with the transfer from the quantum state to the classic state, paying particular attention to the nanometric and mesoscopic fields,
  • Self-assembly of molecular species 2D or 3D ordered networks. The flexibility of molecular chemistry (amphiphilic or polyphilic molecules, anisotropic, etc.) associated with Langmuir Blodgett type techniques, may be efficient in this perspective,
  • Addressing of entities organised on a surface through near field microscopy.
In essence, this field is multidisciplinary, with competencies required in synthetic chemistry, experimental (use of techniques such as micro-SQUID, micro-Hall probe, near field microscopies, strong fields, etc.) and theoretical physics. This explains the strong tradition of collaboration between chemists and physicists at a national level.
          
 
 
 
This network is funded by the French programme on nanosciences,
involving the French Ministry of Research, CNRS and CEA


Maintained by the Institut de Physique et Chimie des Matériaux de Strasbourg.
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webmaster@ipcms.u-strasbg.fr
 
Conception et réalisation : Heptades, solutions multimédia - Ligne graphique : Atelier C