Brillouin scattering from C-70 and C-60 films: a comparative study of elastic properties

Abstract

Brillouin scattering measurements carried out on a thin film of C-70 deposited on a Si(100) substrate show modes at 4.8 and 25 GHz due to the surface Rayleigh wave and the bulk longitudinal acoustic mode, respectively, the corresponding modes for C-60 being found at 4.3 and 30 GHz. Based on the Brillouin data, the values of the bulk, shear and Young's moduli of C-70 are found to be 11.3, 3.2 and 8.7 GPa, respectively (the corresponding values for C-60 are 14.9, 4.7 and 12.7 GPa). Poisson's ratios for Cio and C60 are comparable, the values being 0.37 and 0.36, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.