X-ray diffraction study of glasses in the system Li2O–SiO2

Abstract

X-ray diffraction patterns have been obtained from Li2O·xSiO2 glasses (x=2, 3, 4). By the Fourier analysis the radial distribution function was evaluated, from which interatomic distance and coordination number were obtained. Their values were compared with those of silica glass and of Li2O·2SiO2 crystal. In Li2O·2SiO2 glass (one phase), the distance of Si–O, O–O and Si–Si was 1.62, 2.65 and 3. 07A, respectively. That is, the structure of short range order of Li2O·2SiO2 glass was almost similar to that of Li2O·2SiO2 crystal. In Li2O·4SiO2 glass, which undergoes phase separation and is composed of SiO2-rich phase and Li2O·2SiO2-rich phase, the fifth peaks in the radial distribution curve were found at about 4.8A and 5.1A. And the radial distribution curve of Li2O·3SiO2, which undergoes slight phase separation, indicated the intermediate value between Li2O·2SiO2 glass and Li2O·4SiO2 glass.