The xNa20.(100-x)Ge02(x=10, 15, 20 mol%) glasses were prepared by the sol-gel method from sodium methoxide and germanium butoxide. The structure of the glasses was investigated by means of x-ray radial distribution function and EXAFS analyses and was compared with that of the corresponding melt derived glasses. It was found that the mode of formation of glasses affects the glass structure, and the fraction of sixfold coordinated Ge4+ ions, N6 in the sol-gel derived glasses is almost twice as large as the melt derived ones. The clustering of Ge06 octahedra in the sol-gel derived glasses to form a group such as [Ge4016]4- found in Na4Ge9020 crystal was proposed. The sol-gel derived glasses were crystallised at lower temperatures than the melt derived ones.
