کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1483934 991617 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular dynamics simulations of calcium aluminate glasses
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Molecular dynamics simulations of calcium aluminate glasses
چکیده انگلیسی

Molecular dynamics simulations of a series of calcium aluminate glasses have been carried out using empirical potentials with a covalent term. The simulations closely reproduce the total neutron correlation function of glasses with 30 and 38 mol% Al2O3 and physical properties such as elastic constants. For compositions close to the eutectic 37 mol% Al2O3, aluminum is tetrahedrally coordinated by oxygen, but the proportion of five-fold and six-fold coordination and also edge-sharing tetrahedra gradually increases with increasing Al2O3 content. The coordination number for oxygen around calcium atoms is close to 6 and this involves a larger coordination at a shorter, well-defined distance, followed by a smaller coordination with a broader range of distances. When the Al2O3 content decreases, the calcium aluminate structure becomes depolymerised and the average ring size increases. Also reported is an X-ray photoelectron spectroscopy measurement on a glass sample with 38 mol% Al2O3, which shows that 38.6 ± 0.9% of the oxygens are non-bridging, in excellent agreement with the simulations.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 352, Issue 8, 1 June 2006, Pages 725–736
نویسندگان
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