Magnetic and electromagnetic characterization of barium hexaferrite ceramics and their polymer matrix composites /

Kaya, Seray
In this study, BaHF-based polymer matrix composites were prepared as potential EM wave absorbing materials. Firstly, BaHF powders and platelets were synthesized by mixed oxide method and by molten salt synthesis (MSS) technique, respectively, which were further used as additives in the EM wave absorbing composites. The effect of molten salt composition on the amount of BaHF phase formation, as well as, on the morphology and magnetic properties of the final products were discussed according to the characterization results. Quantitative XRD results showed that with the increase in NaCl flux content, BaHF formation was enhanced and the highest conversion (97.8 wt%) was obtained in the case of 100 wt% NaCl flux. Corners of the BaHF platelets in NaCl flux were rounded, while KCl flux produced sharp edge platelets. Increasing NaCl content in the flux improved the coercivity and remnant magnetization of BaHF, leading to a more pronounced hard magnetic behavior. vi In the second part of the study, BaHF-based polymer matrix composites were prepared by tape casting method, and their electromagnetic wave absorption potentials were investigated within 18-40 GHz frequency range by free-space measurement method. Effect of BaHF content and alignment on the EM wave properties was investigated. To enhance the EM wave absorption potential of the resulting composites, graphite or nickel flakes were incorporated into polymer matrix, and multilayered composites were produced. BaHF-Ni flake containing composites revealed 50-75% EM wave absorption in 18-40 GHz range with the synergistic effect of the magnetic and ohmic loss effective in the structure.


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Hashimov, Arif Mamed; Tabatabaei, Naser Mahdavi; Samedova, Ulker Farruk; Nuriyev, Musa Abdulali; Bayramov, Mazahir Nasraddin; Mehrabov, Amdulla (2019-01-01)
In this paper, we have successfully synthesized nanoparticles of Fe3O4 and composites based on epoxy resin with various mass ratios of nanomagnetite were prepared. The structure, morphology and properties of the composites were characterized with X-ray diffraction, scanning electron microscope. Results of measurements of reflection coefficients (R), transmission (T), and absorption (A) of the ER series composites of composites on basis of nano magnetite are presented in this paper.
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Dalgıç, Ali Deniz; Tezcaner, Ayşen; Keskin, Dilek; Evis, Zafer (SAGE Publications, 2018-3-15)
In this study, novel graphene oxide-incorporated silicate-doped nano-hydroxyapatite composites were prepared and their potential use for bone tissue engineering was investigated by developing an electrospun poly(epsilon-caprolactone) scaffold. Nanocomposite groups were synthesized to have two different ratios of graphene oxide (2 and 4 wt%) to evaluate the effect of graphene oxide incorporation and groups with different silicate-doped nano-hydroxyapatite content was prepared to investigate optimum concentra...
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Duman, Nagehan; Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (2013-12-01)
Much of the recent metallic glass research is devoted to controlling the crystallization of amorphous precursors with the purpose of obtaining amorphous matrix nanocrystalline alloys which combine unmatched soft magnetic properties with good mechanical properties. Therefore, it is crucial to have better understanding of crystallization mechanisms and thermal dependence of nanocrystals that are formed by annealing. This study deals with the nanociystallization kinetics of Cu-modified Fe-Co-Ni-B-Si-Nb bulk am...
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In this study, first, magnetic nanoparticles (MNP) were synthesized using a coprecipitation method and the synthesized particles were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM). According to DLS and VSM analyses results, it was seen that the size of the MNP was smaller than 10 nm and they exhibited superparamagnetic properties, respectively. Then, magnetic Fe3O4-chitosan micro/n...
Induction thermal plasma synthesis of Mg2Ni nanoparticles
Aktekin, Burak; ÇAKMAK, GÜLHAN; Öztürk, Tayfur (2014-06-15)
A study was carried out into possibility of thermal plasma synthesis of Mg2Ni nanoparticles. Both prealloyed powders and elemental powders were used as precursors in an inductively coupled thermal plasma incorporating two injection probes located axially in the reactor one from the top and the other from the bottom. The study has shown that the use of prealloyed Mg2Ni as precursor leads to its disintegration in the plasma condensing into separate phases and therefore was not suitable for the synthesis of Mg...
Citation Formats
S. Kaya, “Magnetic and electromagnetic characterization of barium hexaferrite ceramics and their polymer matrix composites /,” M.S. - Master of Science, Middle East Technical University, 2014.