Study of hematite-iron phase transformation during iron-carbon core-shell nanoparticles synthesis and investigation of their magnetic and microwave properties

• Main Authors: Omid Khani, Morteza Zargar Shoushtari, Mohammad Jazirehpour, Mansoor Farbod
• Format: Article
• Language: English
• Published: Isfahan University of Technology 2017-11-01
• Series: Iranian Journal of Physics Research
• Subjects: Iron-carbon core-shell nanoparticles; Hydrothermal method; Hematite-iron phase transformation; microwave absorber.
• Online Access: http://ijpr.iut.ac.ir/browse.php?a_code=A-10-2529-1&slc_lang=en&sid=1
• ISSN: 1682-6957; 2345-3664

The structural properties and microwave absorption capability of the iron nanoparticles and iron-carbon core-shell nanoparticles have been studied, in the present paper. The investigated nanoparticles were synthesized by hydrothermal route and by reduction of hematite nanoparticles during annealing in argon-hydrogen atmosphere. Hematite-iron phase transformation during the reduction process has been studied by X-ray diffraction (XRD). XRD patterns showed that in iron nanoparticles, hematite-iron phase transformation was completed after 30 min annealing whereas about iron-carbon nanoparticles, the phase transformation completion occurred after 65 min, and before 65 min annealing, wustite (FeO) phase was still present in XRD patterns. M-H loops and relative complex permittivity (ε) and permeability (µ) of the iron nanoparticles and iron-carbon nanocapsules were investigated too. According to the ε and µ spectra in 1-18 GHz, the carbon shell can affect microwave properties of the iron nanoparticles. Carbon shell can reduce microwave permeability and permittivity of the composites containing iron nanoparticles.