Iron–cobalt–graphite core–shell nanoparticles as efficient electromagnetic wave absorbers at X‐band frequency range. (1st June 2014)

• Record Type: Journal Article
• Authors: Seyyed Afghahi, Seyyed Salman; Shokuhfar, Ali; Saberi, Behzad; Javidan, Abdollah
• Is Part Of: Micro & nano letters. Volume 9:Number 6(2014)
• Page Start: 412
• Page End: 416
• Publication Date: 2014-06-01
• Subjects: electromagnetic wave absorption -- nanocomposites -- dielectric losses -- filled polymers -- nanoparticles -- graphite -- cobalt -- iron; core‐shell nanoparticles -- electromagnetic wave absorbers -- graphit ‐coated iron‐cobalt nanoparticles -- nanocomposites -- paraffin matrix -- reflection loss -- scattering parameter -- active dielectric‐magnetic loss mechanisms -- frequency 8 GHz to 12.4 GHz -- FeCo‐C; Nanotechnology -- Periodicals; Nanostructures -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1049/mnl.2013.0723
• Languages: English
• ISSNs: 1750-0443

Abstract

Abstract : In this reported work, FeCo@C core–shell nanoparticles were synthesised using a novel two‐step process. Characterisation of samples confirms the formation of graphite‐coated FeCo nanoparticles. The electromagnetic wave absorption of nanocomposites containing 40%wt of FeCo@C and FeCo nanoparticles in the paraffin matrix was measured at 8–12.4 GHz frequency range. Two samples were prepared with thickness of 9 mm for FeCo and FeCo@C nanoparticles, respectively. Then the reflection loss was measured at ten different thicknesses between 9 and 1.4 mm by slicing the samples and measuring the scattering parameter S 11 for each sample thickness using a metal backing. Results show that by graphite coating of FeCo nanoparticles the maximum reflection loss (−5.5 dB) grows up to four times higher (−19.2 dB) and the corresponding thickness reduces to half. The reason lies in active dielectric‐magnetic loss mechanisms in FeCo@C nanoparticles.