Raman, Brillouin, and nuclear magnetic resonance spectroscopic studies on shocked borosilicate glass

Using Brillouin and Raman scattering and NMR techniques, we have investigated the elastic and structural properties of four post-shocked specimens of borosilicate glass, recovered from peak pressures of 19.8, 31.3, 40.3, and 49.1 GPa. The Raman spectra of shock-wave compressed borosilicate glass for peak pressures of 19.8 and 31.3 GPa show two new peaks at 606 cm−1 and near 1600 cm−1, while a peak at ∼923 cm−1 disappears in these glasses following shock-loading. The mode at 606 cm−1 is correlated with four-membered rings, composed of one BO4 and three SiO4 tetrahedra (a reedmergneritelike configuration). Modes near ∼1600 cm−1 are of uncertain origin, while that at 923 cm−1 may associated with silica tetrahedra with two nonbridging oxygens, although standard models of this type of glass suggest that total nonbridging oxygen contents should be low. The Raman spectra for the shocked samples at 40.3 and 49.1 GPa are similar to that of the unshocked sample, suggesting that much of the irreversible density and ...