کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5441470 | 1510395 | 2016 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular dynamics study of liquid silica under high pressure
ترجمه فارسی عنوان
مطالعه دینامیک مولکولی سیلیس مایع تحت فشار بالا
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کلمات کلیدی
سیلیکا، دینامیک مولکولی، ساختار، نفوذ،
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
چکیده انگلیسی
Structural changes of liquid silica are investigated under high pressure by molecular dynamics simulation. It is well known that high-silica liquids display anomalous pressure-dependent behavior in their diffusivities. The potential model, the so-called 'soft potential', is used, as it is expected to simulate the structural changes of silica at high temperature well. With increasing pressure, above the glass transition temperature, the simulated silica melt shows the so-called diffusivity maximum under a pressure of 20Â GPa, as already shown by the previous studies. However, it is also found that this diffusivity maximum disappears above 2800Â K. The analysis of Si coordination number suggests that the competition between the increase of five-fold and that of three-fold controls the extent of the anomaly. Secondly, the analysis of 'local oxygen packing number (LOPN)', that had been developed to investigate geometrical features in amorphous structures, is applied. In a complementary manner to the analysis of the Si coordination number, the local structure in the silica melt shows the gradual structural transformation from a low-density to high density packing on compression. Finally, a model explaining the two types of change of diffusivity in silica melt was proposed in combination with the LOPN analysis and the structon analysis that had been developed to investigate the thermal change of local structures.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 451, 1 November 2016, Pages 124-130
Journal: Journal of Non-Crystalline Solids - Volume 451, 1 November 2016, Pages 124-130
نویسندگان
Akira Takada, Robert G. Bell, C. Richard A. Catlow,