X-ray spectroscopic investigation of the structure of silica,silicates and oxides in the crystalline and vitreous state

The Si Kα_1,2 emission lines and their satellite lines α′, α₃ and α₄ were measured for several samples of vitreous silica (Suprasil W, Infrasil, Suprasil), sodium silicate glasses (8, 15, 20 and 25 wt% Na₂O), and crystalline Mg₂SiO₄ (Forsterite). The observed shifts of the peak positions indicate a systematic increase of the electron density on the silicon atoms with increasing break-up of the SiO₂ network by OH^? or alkali ions. These results are compared with information from the corresponding Si Kβ and O K emission bands and also with the O K emission bands from quartz, MgO and Al₂O₃. They are discussed on the basis of the MO theory and are compared with the characteristic physical properties and structure of silica and silicate glasses. Both the O K and Si Kβ emission bands are closely related to the electronegativities of the relevant metal atoms of the oxides and glasses.