Abstract EN:

Molecular spintronics is an emerging field of molecular electronics addressing the encoding of information with spins instead of charges. To date, few devices based on break junction techniques have been reported. They display interesting phenomena such as Kondo effect or quantum tunneling of the magnetization. However, quantitative explanation of the transport properties are often limited by uncertainties on the nature of the species within the junction. Recently, the use of carbon nanotubes as molecular wire for spintronics transistors has attracted much attention because of their large spin coherence length. The present work aimed at assemble magnetic objects on SWNTs for spintronics applications. These assemblies have been extensively characterized in bulk material in order to get a detailed picture of the magnetic objects to be integrated in future transistors. To study their magnetic properties, one needs to achieve a high quality purification of SWNTs, which contain about 20% of magnetic impurities as raw material. We developed such a purification and suggested a mechanism for the removing of magnetic impurities. The purified SWNTs have been functionalized with magnetic objects, following non-covalent schemes that preserve the electronic properties of the molecular wire. Three magnetic systems have been selected, including polyoxometalate, coordination nanoparticles and complexes bearing large aromatic moieties. In some cases, an electronic communication between the nanotube and the grafted object was evidenced, that led to a modulation of its magnetic properties. Hence, the assemblies developed in this work hold great promise for future spintronics devices.