کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1404381 1501902 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of copper ions on the precipitation of goethite and hematite in highly alkaline media
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Influence of copper ions on the precipitation of goethite and hematite in highly alkaline media
چکیده انگلیسی
The effects of Cu-dopant on the precipitation of α-FeOOH and α-Fe2O3 particles in highly alkaline media were investigated using 57Fe Mössbauer and Fourier transform infrared (FT-IR) spectroscopies and thermal field emission scanning electron microscopy (FE SEM). Only α-(Fe, Cu)OOH solid solutions were obtained between r = 0.0099 and 0.0291, where r = [Cu]/([Cu] + [Fe]). A mixture of α-(Fe, Cu)OOH and α-(Fe, Cu)2O3 solid solutions was obtained between r = 0.0385 and 0.0566, whereas only an α-(Fe, Cu)2O3 solid solution was obtained between r = 0.0698 and 0.1666. Cu-substitutions in α-(Fe, Cu)OOH and α-(Fe, Cu)2O3 decreased the hyperfine magnetic field 〈Bhf〉 values. With increased Cu-substitution in an α-FeOOH type structure the IR shifts were observed. With an increased r value of initial solution a gradual elongation of α-(Fe, Cu)OOH particles along the crystallographic c-axis was observed. At r = 0.0476, some α-(Fe, Cu)OOH particles were ∼700 nm long, and correspondingly the width and thickness of these particles decreased markedly. With a further increase in r the length of α-(Fe, Cu)OOH particles decreased. α-(Fe, Cu)2O3 particles showed varying sizes in dependence on the precipitation conditions, whereas their geometrical shapes matched those typical of α-Fe2O3.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volumes 834–836, 27 May 2007, Pages 154-161
نویسندگان
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