Vibrational spectroscopic and X-ray diffraction study of crystalline phases in the Li2O-SiO2 system

x Li 2 O · (100 − x )SiO 2 phases, where x = 20, 25, 33, 40, 50, 55, and 60 mol % (hereinafter, Li20, Li25, Li33, Li40, Li50, Li55, and Li60) were crystallized from melts, and their qualitative composition was determined by X-ray diffraction. The Li 6 Si 2 O 7 phase was established to precipitate during the crystallization of the melt containing 60 mol % Li 2 O, thus enabling us to locate characteristic bands in the IR and Raman spectra of lithium pyrosilicate.