کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8156722 | 1524851 | 2014 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Two step synthesis, electromagnetic and microwave absorbing properties of FeCo@C core-shell nanostructure
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Two step synthesis, electromagnetic and microwave absorbing properties of FeCo@C core-shell nanostructure Two step synthesis, electromagnetic and microwave absorbing properties of FeCo@C core-shell nanostructure](/preview/png/8156722.png)
چکیده انگلیسی
In this research synthesis of FeCo@C core-shell nanoparticles was done using a novel two step process including the microemulsion technique and alcohol catalytic chemical vapor deposition. X-ray diffraction, transmission electron microscopy, electron beam diffraction and energy dispersive spectroscopy confirm the formation of FeCo@graphite core-shell nanostructure. Compared with FeCo nanoparticles with an oxide shell, the graphite shell restricts the growth of the FeCo nanoparticles, leading to lower saturation magnetization and higher natural-resonance frequency. The electromagnetic characteristics including permittivity, permeability and loss tangents of FeCo nanoparticles/nanoencapsulates were determined in the frequency range of 2-18 GHz. Results show that the graphite coating dramatically improves electromagnetic wave absorption of FeCo nanoparticles due to several dielectric/magnetic loss mechanisms. The main mechanism enhancing the dielectric loss tangent is Deby׳s dual relaxation phenomenon and for magnetic loss is the ferromagnetic resonance. The maximum reflection loss of â40 dB at 2.5 mm thickness and the maximum effective absorption bandwidth (RL<â20 dB) of 5.6 GHz at 3 mm thickness were obtained for FeCo nanoencapsulates.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 370, December 2014, Pages 37-44
Journal: Journal of Magnetism and Magnetic Materials - Volume 370, December 2014, Pages 37-44
نویسندگان
S.S.S. Afghahi, A. Shokuhfar,