A NEUTRON SCATTERING STUDY OF THE DENSITY OF VIBRATIONAL STATES OF FRACTAL SILICA AEROGELS

G. Coddens , R. Vacher , T. Woignier , J. Pelous , E. Courtens

The various methods to measure the density of states by neutron inelastic scattering are discussed. Purely incoherent scattering data on silica aerogels have been obtained by taking the difference spectra between protonated and identical deuterated samples. The results so far cover the particles modes and the upper part of the fracton regime. Complemented with Brillouin scattering information, these measurements provide an overall picture of the absolute density of states, from which low temperature thermal properties can be calculated, in remarkable agreement with experiments.

Domaines: Articles anciens

G. Coddens, R. Vacher, T. Woignier, J. Pelous, E. Courtens. A NEUTRON SCATTERING STUDY OF THE DENSITY OF VIBRATIONAL STATES OF FRACTAL SILICA AEROGELS. Journal de Physique Colloques, 1989, 50 (C4), pp.C4-151-C4-156. ⟨10.1051/jphyscol:1989424⟩. ⟨jpa-00229500⟩