Interpretation and modeling of IR-reflectance spectra of glasses considering medium range order

Consolidated silica glass from nanoparticles

“…The peak at 1123 cm À1 in the spectra is attributed to the asymmetric Si-O-Si stretching vibration (AS). The shoulder at 1220 cm À1 is usually accepted as being caused by the longitudinal optical phonon of the same vibration [19,20]. An alternative interpretation would be that both features are due to transversal optical excitations of two different AS modes called AS 1 and AS 2 [21][22][23][24].…”

Possible differences between the surface and bulk structure of glasses

“…At this point, it is worth mentioning that infrared reflectance spectroscopy, another method with a probing depth on the order of a few lm is, due to very broad vibration bands, not capable of clearly distinguishing between fourfold and fivefold co-ordination of titanium in fresnoite glasses [20]. Very puzzling, however, are XPS measurements of ion-beam cleaned glass surfaces in which three co-ordination environments are observed (15% [4] Ti 4+ , 61% ' [5] Ti 4+ , 24% [6] Ti 4+ ) [4].…”

Raman and infrared structural investigation of (PbO)x(ZnO)(0.6−x)(P2O5)0.4 glasses

“…Nevertheless, the interpretation and modelling of IR reflectance spectra of glasses are still difficult and need further improvements. [24] Conclusion Using Raman and infrared spectroscopies, we have investigated the structure of ternary (PbO) x (ZnO) (0.6−x) (P 2 O 5 ) 0.4 glasses over the compositional range from x = 0 to 0.6. The linewidths and wavenumbers variations of the Raman high-wavenumber bands reflect the Zn/Pb substitution in these glasses and are correlated with the metal-oxygen force constant and local disorder.…”