کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9781668 | 1511634 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of preheating on diaspore: Modifications in colour centres, structure and light emission
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The thermal properties and thermal stability of diaspore-corundum (AlOOH-Al2O3), from Goian (Pontevedra, Spain) were studied by means of differential thermal analysis (DTA), thermogravimetry (TG), high temperature X-ray diffraction (HTXRD) and thermally stimulated luminescence (TL) techniques. The samples were annealed to link the combined effect of (i) dehydroxylation, (ii) oxidation-reduction of chromophores (Mn 0.5%, Fe2O3 0.12%, TiO2 0.021% and Cr 80 ppm) determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and (iii) phase transitions whilst sample heating (i.e. α-AlOOHâαâ²-Al2P3âα-Al2O3). The blue colour of diaspore, attributed to the Ti4+-Fe2+ intervalence-charge-transfer mechanism, turns to white (circa 500 °C) in good agreement with the DTA endothermic peak (dehydroxylation). The coexistence of α-AlOOH and αâ²-Al2P3 phases has been detected by in situ HTXRD and could be correlated to the thermoluminescence tests performed on preheated aliquots (up to 500 °C).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 7, July 2005, Pages 1220-1227
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 7, July 2005, Pages 1220-1227
نویسندگان
J. Garcia-Guinea, V. Correcher, J. Rubio, F.J. Valle-Fuentes,