کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9778148 1510572 2005 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Vibrational properties of a sodium tetrasilicate glass: Ab initio versus classical force fields
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Vibrational properties of a sodium tetrasilicate glass: Ab initio versus classical force fields
چکیده انگلیسی
We have determined the vibrational properties of a sodium tetrasilicate (Na2Si4O9) glass model generated by molecular dynamics simulations. The study has been carried out using a classical valence force fields approach as well as an ab initio approach in the framework of the density functional theory. The total and partial vibrational densities of states (VDOS) are presented, as well as some characteristics of the vibrational modes (participation ratios, correlation lengths). For the low-frequency bands below 500 cm−1, we find that the shapes of the two calculated VDOS as well as those of their corresponding partial VDOS are quite similar. For the intermediate- and high-frequency ranges, we observe larger discrepancies between the two calculations. Using the eigenmodes of the dynamical matrix we also calculate the polarized Raman spectra within the bond-polarizability approximation. We find an overall agreement between the calculated parallel polarized (VV) Raman spectra and the corresponding experimental spectrum. Regarding the perpendicular depolarized (VH) Raman spectrum, the comparison of the calculated spectra to the experimental data indicates a need for an adjustment of the VH bond-polarizability parameters.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 351, Issues 12–13, 1 May 2005, Pages 1144-1150
نویسندگان
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