کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10629805 | 991184 | 2005 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The thermally induced transformation of pseudoboehmite gels-a comparison of the effects of corundum seeding and iron doping
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: The thermally induced transformation of pseudoboehmite gels-a comparison of the effects of corundum seeding and iron doping The thermally induced transformation of pseudoboehmite gels-a comparison of the effects of corundum seeding and iron doping](/preview/png/10629805.png)
چکیده انگلیسی
The transformation of doped or seeded pseudoboehmite to corundum was studied by combining thermal analysis, X-ray diffraction, transmission electron microscopy, and electron paramagnetic resonance spectroscopy. The temperature of phase transformation to corundum was lowered by about 130 °C when Fe3+ or corundum seeds were added to the sols. Action of Fe3+ ions depends on the actual degree of thermally induced transformation of pseudoboehmite via transition aluminas to corundum and the ability of these alumina phases to incorporate Fe3+ ions. These ions tend to aggregate with increasing iron concentration of the alumina phases and can work as nucleation centers. Small (â¼20 nm) corundum particles act as active nucleation sites whereas larger grains (200-400 nm) also present in the samples are less effective. For the first time trapping and stabilization of NO2 molecules in transition aluminas formed by a sol-gel route was shown.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 25, Issue 7, May 2005, Pages 1095-1107
Journal: Journal of the European Ceramic Society - Volume 25, Issue 7, May 2005, Pages 1095-1107
نویسندگان
M. Nofz, R. Stösser, G. Scholz, I. Dörfel, D. Schultze,