STRUCTURAL STUDIES ON AMORPHOUS SI2O3 AND H2SI2O4 BY MEANS OF DIFFRACTION USING HIGH-ENERGY PHOTONS

The structures of amorphous Si2O3 and H2Si2O4 have been investigated u sing X-ray diffraction with synchrotron radiation at 80 and 120 keV. C onsidering the geometrical limits of the used diffractometer this lead s to the range of momentum transfer from 0.8 to 29 Angstrom(-1). The s tructure factors and the pair correlation functions show that the curv es are more damped for the silicon sesquioxide Si2O3 From the pair cor relation functions of both substances, we retrieve a nearest neighbour distance of about 1.6 Angstrom as is typical for a Si-O bond for tetr ahedrally coordinated silicon and of about 2.3 Angstrom that can be re lated to a direct Si-Si coordination. (C) 1998 Elsevier Science B.V. A ll rights reserved.