scholarly journals Densification effects on the Boson peak in vitreous silica: A molecular-dynamics study

2000 ◽  
Vol 113 (7) ◽  
pp. 2768-2771 ◽  
Author(s):  
P. Jund ◽  
R. Jullien
2021 ◽  
Vol 11 (15) ◽  
pp. 6733
Author(s):  
Mira Naftaly ◽  
Andrew Gregory

Z-cut single-crystal quartz and vitreous silica (silica glass or fused silica) were evaluated for use as reference materials for terahertz and microwave measurements of complex permittivity, with Z-cut quartz confirmed as being suitable. Measurements of refractive indices and absorption coefficients for o-ray and e-ray in quartz and for vitreous silica are reported at frequencies between 0.2 and 6 THz and at 36 and 144 GHz, and compared with data reported in the literature. A previously unreported broad band was seen in the extraordinary absorption of quartz. The Boson peak in silica glass absorption was examined, and for the first time, two negative relationships have been observed: between the refractive index and the Boson peak frequency, and between the Boson peak height and its frequency.


2002 ◽  
Vol 731 ◽  
Author(s):  
Romulo Ochoa ◽  
Michael Arief ◽  
Joseph H. Simmons

AbstractWe conduct molecular dynamics computer simulations of fracture in silica glass using the van Beest, Kramer, and van Santen model. Stress is applied by uniaxial strain at different pulling rates. Comparisons with previous fracture simulations of silica that used the Soules force function are presented. We find that in both models stress is relieved by rotation of the (SiO4)-2 tetrahedrons, increasing Si-O-Si bonding angles, and only small changes in the tetrahedron dimensions and O-Si-O angles.


1998 ◽  
Vol 57 (6) ◽  
pp. R6277-R6280 ◽  
Author(s):  
Alessandro Paciaroni ◽  
Anna Rita Bizzarri ◽  
Salvatore Cannistraro

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