1. INRA, UMR FARE 614, Fractionation of Agricultural Resources and Environment, CREA, 2 Espl. R. Garros, F-51686 Reims, France
2. Université Reims-Champagne-Ardennes (URCA), UMR FARE 614, F-51686 Reims, France
3. Laboratoire de Microscopies et d'Etude de Nanostructures, Université Champagne-Ardennes, 21 Rue Clément Ader, BP 138, F-51685 Reims, France
4. Laboratory of Chemistry and Physics, Erevan State University, 1 A. Manoukian Street, 0025 Erevan, Armenia
5. Present address: Ecole Française de Papeterie et des Industries Graphiques, Institut National Polytechnique de Grenoble, BP 65, F-38402 St Martin d'Hères Cedex, France
6. Institute of Electronics, Micro-electronics and Nanotechnology, IEMN, Cité Scientifique, Avenue Poincaré, BP 60069, F-59652 Villeneuve d'Ascq Cedex, France