Isolation of Co nanoparticles by C60 molecules in co-deposited film

Mixed Co-C-60 films have been prepared on (0001) alpha-Al2O3 or (001) NaCl substrates at room temperature (RT) by simultaneous deposition of cobalt and C-60 fullerene. The characterization of these films by atomic force microscopy (AFM) and high-resolution transmission electron microscopy (TEM) reveals a nanocomposite structure of the films with Co nanocrystals dispersed into carbon-based matrix. Electron and X-ray diffraction (XRD) analyses evidence the face-centered cubic (fcc) lattice of Co nanocrystals. Raman experiments confirm the existence of C-60 molecules as the main structure units of the matrix. Some modification in C-60 Raman modes reflects the distortion of C-60 molecules through CO-C-60 bonding within the matrix of the nanocomposite. (C) 2003 Elsevier Science B.V. All rights reserved.