Vibrations in amorphous silica
نویسندگان
چکیده
منابع مشابه
Thermal conductivity accumulation in amorphous silica and amorphous silicon
We predict the properties of the propagating and nonpropagating vibrational modes in amorphous silica (a-SiO2) and amorphous silicon (a-Si) and, from them, thermal conductivity accumulation functions. The calculations are performed using molecular dynamics simulations, lattice dynamics calculations, and theoretical models. For a-SiO2, the propagating modes contribute negligibly to thermal condu...
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Numerical studies of amorphous silicon show that the lowest 4% of vibrational modes are plane-wave like (“propagons”) and the highest 3% of modes are localized (“locons”). The rest are neither plane-wave like nor localized. We call them “diffusons.” Since diffusons are by far the most numerous, we try to characterize them by calculating such properties as wavevector and polarization (which seem...
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We use molecular dynamics computer simulations to calculate the frequency dependence of the specific heat of a SiO2 melt. The ions interact with the BKS potential and the simulations are done in the NVE ensemble. We find that the frequency dependence of the specific heat shows qualitatively the same behavior as the one of structural quantities, in that at high frequencies a microscopic peak is ...
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We present the results of extensive molecular dynamics computer simulations in which the high frequency dynamics of silica, ν > 0.5 THz, is investigated in the viscous liquid state as well as in the glass state. We characterize the properties of high frequency sound modes by analyzing Jl(q, ν) and Jt(q, ν), the longitudinal and transverse current correlation function, respectively. For wave–vec...
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ژورنال
عنوان ژورنال: Journal of Non-Crystalline Solids
سال: 2016
ISSN: 0022-3093
DOI: 10.1016/j.jnoncrysol.2016.02.002