کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1483407 1510510 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure of potassium germanophosphate glasses by X-ray and neutron diffraction: 3. Reverse Monte Carlo simulations
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Structure of potassium germanophosphate glasses by X-ray and neutron diffraction: 3. Reverse Monte Carlo simulations
چکیده انگلیسی

Reverse Monte Carlo (RMC) is used to investigate the origin of the first sharp diffraction peaks (FSDP) found for K2O–GeO2–P2O5 glasses at very small scattering vector Q = ∼7.5 nm−1. Structures of the ternary glass with the greatest intensity of FSDP (KGeP5 – 25/50/25 mol% K2O/GeO2/P2O5), of the binary combinations of the three oxides and of vitreous GeO2 are modeled. Results are deduced from comparisons of the partial structure factors and inspections of model sections. The P sites are uniformly distributed in the structure of KGeP5. The K+ ions interact more with the PO4 units (via OT-corners) than with Ge-centered units. Main component of the FSDP comes from the SGeGe(Q) factor. The FSDP is due to separations of ∼1 nm between the longish Ge-rich clusters which are visible in the corresponding models. Different to our tentative structural models reported before, the PO4 tetrahedra possess a broad distribution of numbers of OT corners. The FSDP’s of the binary K2O–GeO2 and K2O–P2O5 glasses (∼10 nm−1) are due to a chemical order between network former and network modifier regions. The MRO of a mixed GeO2–P2O5 glass of small P2O5 content (FSDP at ∼16 nm−1) shows great similarity to the MRO of vitreous GeO2.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 355, Issues 31–33, 1 September 2009, Pages 1644–1652
نویسندگان
,