Article

Magnesium Ferrite (MgFe2O4) Nanostructures Fabricated by Electrospinning

Khon Kaen University Department of Physics, Faculty of Science, Small & Strong Materials Group (SSMG) Khon Kaen 40002 Thailand
Nanoscale Research Letters (Impact Factor: 2.78). 03/2008; 4(3):221-228. DOI: 10.1007/s11671-008-9229-y
Source: PubMed

ABSTRACT

Magnesium ferrite (MgFe(2)O(4)) nanostructures were successfully fabricated by electrospinning method. X-ray diffraction, FT-IR, scanning electron microscopy, and transmission electron microscopy revealed that calcination of the as-spun MgFe(2)O(4)/poly(vinyl pyrrolidone) (PVP) composite nanofibers at 500-800 degrees C in air for 2 h resulted in well-developed spinel MgFe(2)O(4) nanostuctures. The crystal structure and morphology of the nanofibers were influenced by the calcination temperature. Crystallite size of the nanoparticles contained in nanofibers increased from 15 +/- 4 to 24 +/- 3 nm when calcination temperature was increased from 500 to 800 degrees C. Room temperature magnetization results showed a ferromagnetic behavior of the calcined MgFe(2)O(4)/PVP composite nanofibers, having their specific saturation magnetization (M(s)) values of 17.0, 20.7, 25.7, and 31.1 emu/g at 10 Oe for the samples calcined at 500, 600, 700, and 800 degrees C, respectively. It is found that the increase in the tendency of M(s) is consistent with the enhancement of crystallinity, and the values of M(s) for the MgFe(2)O(4) samples were observed to increase with increasing crystallite size.

    • "Broadening of the peaks confirmed nano crystalline nature of the sample. Lattice constant is also comparable with the literature values[28]. XRD pattern of NFBC showed peaks corresponding to MgFe 2 O 4 NPs (Fig. 1b) and peaks showing crystalline nature of bentonite clay (Fig. 1c) were absent. "
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    ABSTRACT: Nano ferrite bentonite clay composite (NFBC) of magnesium ferrite nanoparticles (MgFe2O4 NPs) and bentonite is synthesized by sol-gel method and characterized by employing transmission electron microscope (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), FT-IR spectroscopy and BET analysis. NFBC displayed higher porosity and surface area as compared to the pristine MgFe2O4 NPs. We explored the effectiveness of NFBC for the removal of Cr (VI) from aqueous solution and the results were compared with the pristine MgFe2O4 NPs. Adsorption data was modelled using Langmuir, Freudlich and Tempkin isotherms. NFBC displayed higher Qm value along with advantageous magnetic properties of MgFe2O4 NPs. Cr (VI) loaded NFBC could be easily regenerated by washing with 0.1 N NaOH and magnetically separated from the solution. Moreover the adsorption effectiveness of 100% was maintained after five adsorption-desorption cycles.
    No preview · Article · Dec 2015 · Journal of Alloys and Compounds
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    • "Recently, magnesium ferrite has attracted a lot of attention because of its excellent magnetic properties and potential applications in various fields such as microwave absorption , catalysis, semi-conductors, sensors, refractories, and lowmagnetic materials [4] [5] [6] [7] [8] [9] [10]. Many synthesis techniques have been developed to prepare magnesium ferrites such as solvothermal reduction method [11], electrospinning technique [12], co-precipitation [13], sol–gelauto combustion method [14], microwave hydrothermal method [15], reverse micelle processing [16] and high-energy ball milling method [17]. Among them, an auto-ignited technique is a promising way to synthesize various nanoparticles. "
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    ABSTRACT: Spark plasma sintering (SPS) is a powerful technique to produce fine grain dense ferrite at low temperature. This work was undertaken to study the effect of sintering temperature on the densification, microstructures and magnetic properties of magnesium ferrite (MgFe2O4). MgFe2O4 nanoparticles were synthesized via sol-gel self-combustion method. The powders were pressed into pellets which were sintered by spark plasma sintering at 700-900°C for 5min under 40MPa. A densification of 95% of the theoretical density of Mg ferrite was achieved in the spark plasma sintered (SPSed) ceramics. The density, grain size and saturation magnetization of SPSed ceramics were found to increase with an increase in sintering temperature. Infrared (IR) spectra exhibit two important vibration bands of tetrahedral and octahedral metal-oxygen sites. The investigations of microstructures and magnetic properties reveal that the unique sintering mechanism in the SPS process is responsible for the enhancement of magnetic properties of SPSed compacts.
    Full-text · Article · Dec 2015
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    • "This may be due to the stretching vibrations between the oxygen atoms and the metal cations (Fe-O) [23] [37] [39]. Based on the above results, we can deduce that PVP have totally decomposed. "
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    ABSTRACT: In this study, we successfully synthesized magnesium ferrite (MgFe2O4) nanofibers by a facile electrospinning technique followed by calcining at 800 °C. The lithium storage properties of MgFe2O4 nanofibers as anode materials for lithium-ion batteries have been discussed for the first time. It is demonstrated that MgFe2O4 nanofibers electrode not only deliver a high initial discharge capacity of around 1304 mAh g−1, but also maintain a reversible capacity of 714 mAh g−1 after 100 cycles. Moreover, the MgFe2O4 nanofibers electrode also exhibits high capacity at higher charge/discharge rate. Even at a current density of 2000 mA g−1, the reversible capacity can attain 409 mAh g−1 after 100 cycles, suggesting its excellent rate capability. The superior lithium storage properties of the MgFe2O4 nanofibers electrode may be related to the unique continuous fibrous morphologies, nanostructured architectures, porous structures, and large specific surface area, which provide an easily Li+ diffusion path and promote electron transfer. In addition, the formation of MgO appears to act as a buffer layer that prevents agglomeration of nanocrystalline, accommodate the large volume change and reduces polarization during cycling.
    Full-text · Article · Feb 2015 · Electrochimica Acta
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