DIFFRACTION STUDY OF LI2O.SIO2 GLASS WITH COMPUTER-SIMULATION

The structure of Li2O.SiO2 glass has been determined by the pair-function analysis of the radial distribution function (RDF) obtained by X-ray and neutron diffraction measurements. The structure models were constructed by the molecular dynamics method (MD). The calculated RDFs, the summation of the pair-functions of the model, were compared with the observed RDFs while varying the MD parameters. Taking advantage of the negative scattering length of Li for neutron diffraction, the glass structure was investigated in detail, and it was found that the chains of SiO4 tetrahedra bend at 20-degrees, which is a little less than for the crystal (23.48-degrees). It is known that the larger the size of the alkali ions (Na+ --> K+ --> Cs+), the smaller the bending angle of the chains. It was found that this rule also applies to Li+.