Structure of alkali borosilicate glasses and melts according to Raman spectroscopy data

Relationship between Molten Oxide Structure and Thermal Conductivity in the CaO–SiO2–B2O3 System

“…It should be noted that a danburite structure of CaO•B2O3•2SiO2 (one BO4 -unit is surrounded by three SiO4 and one BO4 -) was not considered which is observed around 630 cm -1 of Raman shift. 40) According to Osipov et al, 42) a danburite spectrum is observed at 614 cm -1 with a complete absence of peaks within the 1 400-1 500 cm -1 range, however, spectra within the range were found almost the entire compositions in the current study. In addition, a fully-polymerized tetrahedral silicate (SiO4) unit, which is an essential component for danburite, was rarely observed.…”

In-situ Raman and Brillouin light scattering study of the international simple glass in response to temperature and pressure

“…of the ISG makes the unambiguous assignment of Raman bands to specific structural units difficult. Its Raman spectrum has the following general features of sodium borosilicate glasses [33,34]: 1) the main band around 500 cm −1 corresponds to the bridging oxygen vibration of the SiO 4 network; 2) the peak around 630 cm −1 is attributed to the breathing mode of borosilicate rings (possibly "loose BO 3 "); 3) the broad peak in the range of 850 to 1200 cm −1 is due to the symmetric stretching vibration of Si-O bonds in Q n species of SiO 4 tetrahedra (1 b n b 4 bridging oxygen); and 4) the weak peak in the region from 1200 to 1550 cm − 1 arises from B-O bond vibration of BO 3 and BO 4 units. Significant intensity changes are seen in the peak around 630 cm −1 and in the broad peak around 950-980 cm −1 , both decrease at and above 600°C.…”

A Raman-spectroscopic study of indentation-induced structural changes in technical alkali-borosilicate glasses with varying silicate network connectivity

“…Both the relative intensity and the shape of the Raman profile from 1000 to 1250 cm −1 are very similar to those observed for SiO 2 , suggesting that the connectivity of the silicate sub-network in KBS resembles that in silica glass as manifested also by infrared spectroscopy. The small intensity build up between 1060 and 1200 cm −1 suggests a very small content of Q 3 silicate tetrahedral units, as their characteristic silicon-oxygen stretching vibration is expected in this frequency range [39,[46][47][48]. It should be noted that the Raman cross section of the stretching modes associated to tetrahedral with NBOs, such as Q 3 groups, is much higher compared to that of fully polymerized Q 4 units.…”

“…The content of trigonal borate units in glass NBS1 should be limited judging by the very weak activity in the 1300 to 1600 cm −1 range, which is in line with the corresponding infrared data. The strong feature of the NBS1 glass spectrum at 1070 cm − 1 shows clearly the presence of Q 3 silicate tetrahedra, while the shoulders at~1150 and 950 cm − 1 are associated with silicate units Q 4 and Q 2 , respectively [46][47][48].…”