INVESTIGATION ON PERMANENTLY DENSIFIED VITREOUS SILICA BY MEANS OF NEUTRON-SCATTERING

We have measured the vibrational density of states (VDOS) of normal an d densified vitreous silica by means of neutron scattering for the fir st time. We have also observed Raman spectrum to find the densificatio n dependencies. Neutron VDOS does not change drastically on densificat ion, except for an energy shift of spectrum, in contrast to Raman spec trum. The paper discusses the evolution of spectra by applying the Sen and Thorpe theory and confirms that the structural change can be main ly attributed to the modification of the intermediate correlations.