Surfaces and interfaces of metal oxides


Scientific aim


Understanding of mechanisms brought into play at the surface and interfaces of metal oxides in interaction with a gas or a solid: reactivity of single-crystal surfaces or nanoparticules, deposits of metals or oxides going from some monolayers to several hundreds of nanometers thick layers.


Research areas


Defects characterization of titanium dioxide single cristal surfaces

  • Use of resonant photoelectron diffraction for studying the local electron structure around chemical species: determination of the nature and of the local environment of point defects resulting from deviation from stoichiometry or from oxidation-reduction reactions in titanium dioxide.

Metal-oxide interactions and elaboration of controlled supported nanostructures

  • Fabrication of supported nanostructures thanks to the control of interfacial reactions.
  • Electron spectroscopies, scanning tunneling microscopy and quantum calculations (DFT) studies.
  • Development of a supported nanostructures elaboration route from the understanding of adsorption and decomposition mechanisms of carbonyl precursors.

Growth mechanisms of tungsten oxides on different supports

  • Study of growth mechanisms of tungsten oxide nanorods on mica surfaces.
  • Cristallographic analysis using transmission electron microscopy.
  • Study of the prominent part played by potassium on the stabilization of different kinds of tungsten oxides.

First stages of Metal Organic Chemical Vapour Deposition (MOCVD) growths

  • Study of interfacial phenomena during MOCVD growth of TiO2 ultra-thin layers: in-situ analysis by electron spectroscopies.
  • Control of interdiffusion phenomena at the interface.
  • Preparation of ultra-thin films of polycationic oxides (barium silicates with sharp interface with the substrate).

Structure and properties of transition metal (Ti, Zr, …) oxi-carbo-nitride thin films

  • Tianium oxinitride thin films for photocatalytic applications.
  • Coloured thin films for decorative use: Ti(C,N,O) Characterizations by electronic spectroscopies, transmission electron microscopy and Raman spectroscopy of Ti(C, N, O) films obtained by PVD as function of growth parameters. Link with the film colour.
  • Fonctionnalization by laser treatment of metallic substrates :
    Structure and properties of the surface layers formed by treatment of titanium substrates with pulsed Nd-YAG lasers. Influence of the different laser parameters on light elements insertion (C, N, O).
  • Coatings for cutting tools:
    Characterization of coatings for increasing lifetime of wood cutting tools : application to 1st and 2d wood transformations.

Innovative experiments or modelizations linked to synchrotron radiation

Surface Enhanced Raman Spectroscopy (SERS)