Raman spectroscopy on SiO2 glasses sintered from nanosized particles

Significance of an amorphous SiO2 phase in a pseudomorph after coesite enclosed in garnet from ultrahigh‐pressure eclogite, Su–Lu Belt, eastern China

“…Raman spectrum of the coesite inclusion (spot 4) within a kyanite grain from the outer segment of the garnet. Raman spectra of the SiO 2 glass (from Ivanda et al, 2003) and standard quartz are also presented extensive activity of supercritical silicate-rich aqueous fluids during the peak metamorphic stage. Recently, however, a prevailing theory of the origin of the quartz+K-feldsparAEalbite assemblage suggests that they likely crystallized from felsic melts due to dehydration melting of phengite (e.g.…”

“…Figure shows Raman spectra of the SiO 2 phases (spots 1 and 2) in the dark‐coloured area of the pseudomorph. The Raman spectrum of a single α‐quartz crystal measured under the same equipment and conditions and the Raman spectrum of SiO 2 glass, reported by Ivanda, Clasen, Hornfeck, and Kiefer (), are also shown in Figure for comparison. The SiO 2 phases at both spots 1 and 2 show broad Raman spectra with weak bands near 459 and 602 cm −1 , but they do not show any definitive Raman bands of α‐quartz at 128, 205 and 464 cm −1 .…”

“…Raman spectrum of the coesite inclusion (spot 4) within a kyanite grain from the outer segment of the garnet. Raman spectra of the SiO 2 glass (from Ivanda et al., ) and standard quartz are also presented…”

Cathodoluminescence of non-stoichiometric silica: The role of oxygen

“…(1) in small clusters as chains or rings in the SiO x network [9], and that could be one of the most evident origins for the Y luminescence in dry silica. In the absence of water there are strained bonds or defects of the form "Si-OÁ Á ÁSi", (where OÁ Á ÁSi represents a strained bond) that could be transformed into non-bridging oxygen hole centers (NBOHC) or oxygen deficient centers (ODC) or even small membered silicon rings [10] as an effect of high temperature treatment, see Fig. 3.…”

FT-Raman spectroscopy study on the effect of ceramic fillers in P(EO)LiBETI

“…5) can be ascribed to the defective band D2 of silica [43], the mode at about 1100 cm À1 remains unassigned and could be associated to the effect of the ceramic filler on the vibrational spectra of the P(EO) 20 LiBETI polymer electrolyte. Modifications of the vibrational modes, especially in the low frequency region, resulting from salt-filler or polymer-filler interactions have been reported [24].…”