کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1803564 1024621 2008 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Magneto-optic Faraday effect in maghemite nanoparticles/silica matrix nanocomposites prepared by the Sol–Gel method
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Magneto-optic Faraday effect in maghemite nanoparticles/silica matrix nanocomposites prepared by the Sol–Gel method
چکیده انگلیسی

Bulk monolithic samples of γ-Fe2O3/SiO2 composites with different iron oxide/silica ratios have been prepared by the sol–gel technique. Iron oxide nanoparticles are obtained in-situ during heat treatment of samples and silica matrix consolidation. Preparation method was previously optimized to minimize the percentage of antiferromagnetic α-Fe2O3 and parallelepipeds of roughly 2×5×12 mm3, with good mechanical stability, are obtained. RT magnetization curves show a non-hysteretic behavior. Thus, magnetization measurements have been well fitted to an expression that combines the Langevin equation with an additional linear term, indicating that some of the nanoparticles are still superparamagnetic as confirmed by X-ray diffraction and electron microscopy measurements. Zero field cooled /field cooled experiments show curves with slightly different shapes, depending on the size and shape distribution of nanoparticles for a given composition. Magneto-optical Faraday effect measurements show that the Faraday rotation is proportional to magnetization of the samples, as expected. As a demonstration of their sensing possibilities, the relative intensity of polarized light, measured at 5° from the extinction angle, was plotted versus applied magnetic field.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 320, Issue 20, October 2008, Pages e725–e729
نویسندگان
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