Accueil > Recherche > Auto-organisation de nanostructures et STM > Stages, thèses, post-docs

New Quantum Materials for Spintronics

publié le

Rémunération éventuelle du stage : oui
Possibilité de poursuivre en thèse ? oui
Si oui, mode de financement envisagé : EDPIF

Techniques utilisées : microscopie et spectroscopie à effet tunnel ; diffraction d’électrons, spectroscopie Auger ; Effet Kerr Magnéto-optique
Qualités du candidat requises : excellent étudiant, gout pour les expériences

Scientific project : pure 2D metals do not exist ! And 2D alloys so do not. But it is possible to create these 2D-metals by using a hint : sandwiched metallic atoms between two graphene layers.
The aim of the internship is to study, at the nanoscale, growth properties of bimetallic alloys obtained by intercalation of metal atoms between two graphene sheets, i.e., 2D alloys. The studies will be performed using scanning tunnelling microscopy techniques (STM) and micro-magnetic measurements.
Graphene, a monoatomic sheet of 1 atom thick, has 2p conjugated π orbitals, which not only confers exceptional physical properties, but in addition the capacity to induce new properties to adsorbed materials as atoms, molecules or … nanoalloys. For example, it has recently been shown that graphene on SiC is a good template to insert gold, cobalt or titanium. It follows that it will be possible to exfoliate the graphene-metal-graphene sandwich and to report it on various substrates to study their spintronic and transport properties.
During the internship, after studies of the synthesis of mono and bi-layers graphene on the Si face of the SiC by Si evaporation from the surface, we will intercalate gold and cobalt atoms. Then, the system AuCo will be synthesized by successive intercalations. Note that the intrinsic properties of graphene will also be modified, for example, one could control its doping by changing the density of intercalated atoms, or to study the effects of interactions between molecules and the interposed metal shielded by the plane of carbon.
Together with usual surface techniques as low energy electrons diffraction or Auger electrons spectroscopy, STM techniques, spectroscopy at atomic scale (STS) and magneto-optical Kerr effect (MOKE) will be used to study different stages of growth and magnetic properties. For example, because of encapsulation, blocking temperature and anisotropic magneto-crystalline energies of ultra-thin films will change.
This may be the opening to a thesis oriented to intercalation of those species under other 2D materials such as phosphorene or TMD. The tunnelling spectroscopy measurements will then be essential.
In short, the purpose of this fundamental research is to explore different ways to control, on one hand, the properties of bimetallic alloys and, on the other hand, changes induced on the graphene by this type of functionalization.

Voir en ligne : mailto:Yann GIRARD<yann.girard@u...

Post-scriptum :

Responsable(s) du stage/PhD thesis : Yann GIRARD
Téléphone : 01 57 27 62 99
e-mail : yann.girard@u-paris.fr