کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1799717 1524866 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of cobalt substitution on magnetic hardening of magnetite
ترجمه فارسی عنوان
اثر جایگزینی کبالت بر سختی مغناطیسی مگنتیت
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
چکیده انگلیسی


• It is possible to get Co substituted magnetite nanoparticles by coprecipitation method.
• Prepared nanoparticles have different cation distribution in comparison with that of bulk counterparts.
• Co substitution increases coercivity of the magnetite.

In this work cobalt-substituted magnetite (CoxFe1−xFe2O4, x=0, 0.25, 0.50 and 0.75) nanoparticles were synthesized by coprecipitation method and their structural and magnetic properties were investigated. X-ray diffraction was carried out and the results show that all of the samples have single phase spinel structure. Microstructure of the samples was studied using a field emission scanning electron microscope and the results show that particle sizes of the prepared nanoparticles were uniform and in the 50–55 nm range. Room temperature magnetic properties of the nanoparticles were measured by an alternating gradient force magnetometer and the results revealed that substituting cobalt for iron in magnetite structure, changes the magnetite from a soft magnetic material to a hard one. So that coercivity changes from 0 (a superparamagnetic state) to 337 Oe (a hard magnetic material), which is a remarkable change. Curie temperatures of the samples were determined by recording their susceptibility-temperature (χ–T) curves and the results show that by increasing cobalt content, Curie temperature of the samples also increases. Also χ–T curves of the samples were recorded from above Curie temperature to room temperature (first cooling), while the curves in the second heating and second cooling have the same behaviour as the first cooling curve. The results depict that all samples have different behaviour in the first cooling and in the first heating processes. This shows remarkable changes of the cation distribution in the course of first heating.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 354, March 2014, Pages 119–124
نویسندگان
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