Short-range and medium-range order in lithium silicate glasses .1. Diffraction experiments and results

Silicate glasses of the composition (Li2O)(x)(SiO2)(100-x) (x = 0, 20, 33.3, and 40) have been prepared and characterized by X-ray and neutron diffraction experiments using the technique of isotopic substitution, Thus, at each composition, a set of independent diffraction patterns allows the discussion of the short-range and medium-range structure, For the short-range structure, average coordination numbers and atomic-pair distances are obtained from the pair-distribution functions, For the medium-range structure, i.e., for atomic-pair distances >0.5 nm, an increase of the amplitudes of the oscillations in the pair-distribution function is observed with increases in the Li2O content.