The structure and dynamics of densified SiO2 glasses have been studied
by neutron scattering and Raman scattering as a function of the densi
ty. The detailed evolution of the intermediate-range structure, which
appears as a change in the first and second diffraction peaks, were cl
early observed and we found that a structural change has a linear prop
ortionality to the density. The low-energy dynamics, the Boson peak, h
ave also a strong correlation with the change of the intermediate-rang
e structure. In this paper we discuss this correlation from the point
of view that the six-fold ring structure has a key role. (C) 1998 Publ
ished by Elsevier Science B.V. All rights reserved.