Ferrite Nanocomposites Research Articles

Development of Nickel Doped Zinc Ferrite Nanocomposites as Magnetically Recoverable Catalytic Material for The Synthesis of Biphenyl Methane

Magnetically active nickel doped zinc ferrite nanoparticles with chemical composition NixZn1-xFe2O4 (x- 0.0, 0.25, 0.5, 0.75 and 1.0) were successfully synthesized by sol-gel auto-combustion method using high purity metal nitrates and ethylene glycol as gelling agent. The prepared samples were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Fluorescence (XRF) and Fourier Transform Infra-Red spectral (FTIR) analyses. TEM images and particle size distribution profile reveals the agglomeration tendency during nickel doping suggest the magnetic nature of particles. The remarkable change in the magnetic behaviour of nickel doped zinc ferrite samples provide an easy recovery and regeneration of the material and thus making an excellent candidate for benzylation reaction without any remarkable fall in the catalytic performance for repeated cycles.

Spinel ferrite nanoparticles and nanocomposites for biomedical applications and their toxicity.

This review focuses on the biomedical applications and toxicity of spinel ferrite nanoparticles (SFNPs) with more emphasis on the recently published work. A critical review is provided on recent advances of SFNPs applications in biomedical areas. The novelty of SFNPs in addressing the bottleneck problems encountered in the areas of health; in particular, for diagnosis and treatment of tumour cells are well reviewed. Furthermore, research gaps, toxicity of SFNPs and areas which still need more attention are highlighted. Based on the result of this review, the SFNPs have unlimited capacity in cancer treatment, disease diagnosis, magnetic resonance imaging, drug delivery and release. Overall, stepping out of the conventional way of treatment is difficult but also essential in bringing long lasting solution for cancer and other diseases treatment. In fact, the toxicity study and commercialisation of the SFNPs based cancer treatment options are the main challenges and need further study, in order to reduce unforeseen consequences.

Structural, Morphological, and Optomagnetic Properties of La/Cu/Cu-Mn Ferrite Ternary Nanocomposites

CuFe2O4 (CF), Cu0.5Mn0.5Fe2O4 (CMF), and Cu0.5Mn0.5Fe1.5La0.5O4 (LCMF) ferrite nanocomposites were synthesized by simple sonochemical reaction. The structural, optical, and magnetic properties of the prepared CF, CMF, and LCMF ferrite nanocomposites were analyzed through x-ray diffraction pattern, Fourier transform infrared spectra, ultraviolet spectra, x-ray photoelectron spectroscopy (XPS), scanning electron microscopy, and vibrating sample magnetometer loop. The crystal size of the LCMF ferrite ternary nanocomposite was less than that of the CF and CMF ferrite nanocomposites. XPS revealed the oxidation state (Cu 2p, Mn 2p, La 3d, Fe 2p, and O 1s) and the binding energy of the element present in the prepared CF, CMF, and LCMF ferrite ternary nanocomposites. The scanning electron microscopy images showed spherical morphology. The optical bandgap energy of LCMF was 5.33 eV higher than that of the CF (1.66 eV) and CMF (2.10 eV) ferrite nanocomposites. The coercivity of the prepared ferrite nanocomposites confirmed soft magnetic nature of the CF, CMF, and LCMF ferrite nanocomposites. By doping a small amount of La3+ ions in CMF nanoferrite, it was found that the doped LCMF ferrite ternary nanocomposite has a high permeability, which enhances the useful magnetic properties of LCMF ferrite nanocomposite for electronic devices. The optical bandgap and high permeability of the LCMF ferrite ternary nanocomposite are more suitable for microwave absorption application.

Composition dependent magnetic and microwave properties of exchange-coupled hard/soft nanocomposite ferrite

In the present work, exchange-coupled BaFe12O19 (BaM)/Ni0.5Zn0.5Fe2O4 (NZFO) nanocomposites with different weight ratio were prepared by sol-gel autocombustion method. The effect of relative weight fraction on structural, morphological, magnetic and microwave properties were investigated. X-ray diffraction patterns of composites confirmed the co-existence of BaM and NZFO phases without any secondary phase. Smooth hysteresis loops without kink confirmed that BaM/NZFO phases were well exchange-coupled. Non linear change in magnetization (Ms) and coercivity (Hc) with NZFO content were observed. The drastic increase in Ms with corresponding sharp decrease in Hc for 70/30 wt ratio was observed. The change in Ms and Hc was explained with the schematic model of interfacial spin interactions. Complex permeability and permittivity in Ku-band showed oscillatory behaviour for higher weight fraction of NZFO. Reflection loss frequency found to depends on NZFO content and maximum loss (−41 dB) was observed for 70/30 wt ratio at 13.8 GHz frequency.

Enhanced photocatalytic and antibacterial activities of RGO/LiFe5O8 nanocomposites

Through a thermal treatment method, LiFe5O8 nanoparticles are prepared and by using situ polymerization method, reduced graphene oxide/lithium ferrite (RGO/LiFe5O8) nanocomposites with the ratios of 0.15, 0.20 and 0.25 are created. The structural and physical properties of prepared samples are analyzed by different techniques. By using degradation of methylene blue (MB), photocatalytic activity is investigated under visible light. The combination of LiFe5O8 nanoparticles with RGO causes the enhancement of photocatalytic activity in same conditions. Moreover, after five recycles, photocatalytic activity of RGO/LiFe5O8 does not change as compared to the photocatalytic activity of fresh catalyst, indicating the stability and reusability of RGO/LiFe5O8. Additionally, the antibacterial characteristics of studied samples were investigated against Staphylococcus aureus (S. aureus) as Gram- positive bacteria and Escherichia coli (E. coli) as a Gram- negative bacteria with inhibition zone and colony counting methods. According to obtained results, the pure LiFe5O8 do not have any antibacterial effect on S. aureus, and E. coli. RGO/LiFe5O8 nanocomposites with the maximum concentration of RGO have a greater antibacterial effect on S. aureus, and E. coli than LiFe5O8 nanoparticles and RGO/LiFe5O8 nanocomposites with lower RGO ratios.

Lithium ferrite (LiFe5O8)/polymethyl methacrylate (PMMA) nano-composite used in high dielectric constant capacitor and electromagnetic applications

Poly methyl methacrylate/ Lithium ferrite nano-composites have been prepared by solution mixing process. The electrical conductivity and dielectric properties of these prepared nano-composite have been investigated in the frequency range 102–106 Hz at different LiFe5O8 concentrations from 0 vol% to 25 vol%. The prepared samples are studied by thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). Moreover, the magnetic properties of these nano-composites are investigated through vibrating sample magnetometer studies. XRD spectral investigation revealed that the structural of PMMA and its chemical characterization are appreciably affected by mixed lithium ferrite filler. The thermal stability of the PMMA matrix was found to increase appreciably by LiFe5O8 loading. The (I-V) characteristic of these nano-composites are in very good agreement with the non-linearity predicted by Kaiser et al. model. The effective dielectric constant is studied through different proposed models. Saturation magnetization of 10.05 emu/g is achieved for PMMA sample loaded with 25 vol% of LiFe5O8 particles.

Facile design of nitrogen-doped reduced graphene oxide/zinc ferrite hybrid nanocomposites with excellent microwave absorption in the X-band

Abstract Herein, nitrogen-doped reduced graphene oxide/zinc ferrite (NRGO/ZnFe2O4) hybrid nanocomposites were synthesized through a facile one-pot hydrothermal strategy by using graphene oxide (GO) as a substrate. Results demonstrated that the additive amounts of GO had remarkable influence on the micromorphology and microwave absorption properties of NRGO/ZnFe2O4 hybrid nanocomposites. The as-prepared hybrid nanocomposites showed good dispersion of nanoparticles as the additive amounts of GO increasing and numerous ZnFe2O4 nanoparticles uniformly loaded on the crumpled surface of thinly flake-like NRGO were observed. It was found that the obtained hybrid nanocomposites exhibited obviously enhanced microwave absorption performance than that of pure ZnFe2O4. Remarkably, the minimum reflection loss reached −54.6 dB at 10.0 GHz (X-band) and effective absorption bandwidth achieved 4.2 GHz (11.8–16.0 GHz) with a thickness of merely 2.0 mm and filler loading of 40 wt%. It was believed that our results could be helpful for designing and fabricating graphene-based composites as high-efficient microwave absorbers.

Magnetic interactions and dielectric behaviour of cobalt ferrite and barium titanate multiferroics nanocomposites

Multiferroics materials have been used widely in various fields such as ceramic supercapacitors, active and multifunctional devices due to their high relative permittivity with magnetic and ferroelectric behavior even at room temperature. The composites of cobalt ferrite, barium titanate have been synthesized through co precipitation technique and sintered at very high temperature1273K. The existence of titanate single phase and cobalt ferrite structural analysis carried out through ‘X’ Ray diffraction analysis. From the AC analysis the role of phase, dielectric constant, loss tangent and conductivity was also studied. AC conductivity variation was very low at lower frequencies and increases with frequency. Magnetization measurements were carried out at room temperature shows soft ferromagnetic property is 2.8089 emu/g.

Cd2+ substituted nickel ferrite doped polyaniline nanocomposites as effective shield against electromagnetic radiation in X-band frequency

Abstract Polyaniline encapsulated Cd 2+ substituted nickel ferrite nanocomposites with different weight ratio (polyaniline/NiCd ferrite = 15, 25 and 30%) have been synthesized via in situ polymerization. The XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), UV–Vis spectra and TEM (Transmission electron microscopy) analysis confirmed the successful formation of conducting–ferromagnetic polymer nanocomposites. Electrical properties (DC) of the samples were measured by the FPR (Four probe resistivity) technique. TGA (Thermo-gravimetric analysis) analysis indicated improved thermal stability of composites with rising ferrite content in the polymer matrix. These nanocomposites exhibit ferromagnetism at room temperature with the increased saturation magnetization from 13.92 to 23.49 emu/g as revealed by VSM (Vibrating sample magnetometer) results. From VNA (Vector network analyzer) study, it was found that the composite containing 30 wt% NiCdFe 2 O 4 showed the maximum SE T (42.7 dB) in X-band range due to the synergistic tuning of magnetic and conductive nanoparticles, presenting them as an effective EMI shield for various electrical, electronic and radiation equipments.

The microstructure and magnetic behavior of spark plasma sintered iron/nickel zinc ferrite nanocomposite synthesized by the complex sol-gel method

In this study, a 2.7 wt% (Fe)/97.3 wt% (Zn0.3Ni0.7Fe2O4) nanocomposite (45–100 nm) was synthesized uisng the non-alkoxide complex sol-gel method by controlling the amount of Triethanolamine (TEA) and the annealing temperature. Various instuments including the simultaneous thermal analyzer (STA), Fourier transform infrared spectrometer, X-ray diffraction, scanning electron microscope equipped with X-ray dispersive spectroscopy, and vibrating sample magnetometer were used to characterize the samples. The STA results showed that the gel was converted from the amorphous phase to a crystalline one at 750 °C. The XRD pattern at the temperature of 750 °C also confirmed the presence of a spinel ferrite structure, α- Fe2O3 and Fe phases. By increasing the annealing temperature to 1100 °C, α- Fe2O3 as an impurity phase was eliminated, but the iron phase (formed through the reduction of the partial Fe3+ ions by TEA molecules as a sacrificial reducing agent) was still present. According to the VSM analysis of the SPSed sample, the exchange coupling between the iron phase and nickel zinc ferrite nanoparticles significantly improved the saturation magnetization of the spinel ferrite from 66.0 emu/g to 82.9 emu/g.

Synthesis and Characterization of Bismuth Ferrite-Nickel Ferrite Nanocomposites

Abstract: A chemical route was used to synthesize perovskite bismuth ferrite and spinel nickel ferrite of bismuth ferrite-nickel ferrite nanocomposites. The precursors mixed were made to undergo thermal analyses to observe the crystallization temperature. Then the precursor samples were heated at 550, 600 and 700 °C for 4 h, followed by XRD analyses to determine phase formation. Crystallite size, strain analyses by the Williamson-Hall plot and planes of orientations were noted from XRD analysis. It was observed that 600 °C was the optimum temperature for phase development. Morphology analyses exhibited an agglomerated mass of particulates, while individual phase particulates were polygonal and irregularly shaped. EDX analysis confirmed the elemental compositions of the sample synthesized, while FTIR analysis confirmed the presence of M-O octahedral and tetrahedral coordinations of the M-O bonds formed.

Sono-assisted rapid adsorption of anionic dye onto magnetic CaFe2O4/MnFe2O4 nanocomposite from aqua matrix

In this research the proficiency of a novel magnetic calcium ferrite and manganese ferrite nanocomposite (CF-MF-NC) was evaluated for adsorptive sequestration of Eriochrome black T (EBT) dye coupled with the ultrasonic irradiation. CF-MF-NC exhibits saturation magnetization of 38.17 emu/g, BET surface area of 47.67m2/g, and average pore diameter of 10.17 nm, which makes it a potential magnetic nano-scale adsorbent. The CF-MF-NC has shown superior adsorptive performance (~88%) towards EBT dye as compared to pure CaFe2O4 (~64%) and MnFe2O4 (~52%) and this may be due to the higher surface reactivity, and enhanced physicochemical properties of the composite. The pseudo-second order kinetic model could explain the sono-assisted adsorption of EBT dye onto CF-MF-NC and the involvement of ultrasound enhanced the diffusion rate. Performance evaluation study reveals that sono-assisted EBT dye adsorption onto CF-MF-NC was superior (~98% of EBT dye removal) to conventional adsorption process with batch stirring (78.33%) and shaker (84.34%).

Remote control of biofouling by heating PDMS/MnZn ferrite nanocomposites with an alternating magnetic field

AbstractBACKGROUNDThe accumulation of unwanted microorganisms on wetted surfaces, leading to surface damage and contamination, is a common and significant global issue.RESULTSHerein, we report a novel technique where the growth of microorganisms can be readily controlled by coating the surfaces with a polydimethylsiloxane (PDMS)/Mn0.8Zn0.2Fe2O4 (manganese‐zinc ferrite) nanocomposite followed by applying alternating magnetic field (AMF). The PDMS/MnZn ferrite nanocomposite is light weight and thermally stable (up to ∼ 330 °C) that can form a flexible coating. PDMS also provides hydrophobicity, which is further enhanced by the addition of Mn and Zn. The improved hydrophobicity makes the coated surface less susceptible to biofilm formation. When external AMF was applied to nanocomposites containing various MnZn ferrite nanoparticle loads of 10%, 20% and 30%, the temperature of the surface of nanocomposites reached to 80, 120 and 160 °C, respectively. Successful biofilm deactivation was achieved by heating the nanocomposites via AMF application, as shown in the biofilm test where up to ∼ 70% of the Pseudomonas aeruginosa PAO1 biofilm cells were killed when the AMF was applied for 20 min to the nanocomposites containing 30% nanoparticles.CONCLUSIONCoating the surface with PDMS/MnZn ferrite nanocomposites followed by applying external AMF can be an effective way to remove biofilm remotely in a wide range of applications. © 2019 Society of Chemical Industry

Structure, magnetic and catalytic properties of SiO2-MFe2O4 (M = Mn, Co, Ni, Cu) nanocomposites and their syntheses by a modified sol–gel method

The structure, magnetic and catalytic properties of silica - ferrite nanocomposites were investigated. A series of SiO2-MFe2O4 (M = Mn, Co, Ni, Cu) composites were synthesized by a sol–gel technique using citric acid and glycerin. The samples were characterized by TGA, XRD, TEM and BET methods. Results of magnetization measurements proved a strong dependence of the saturation magnetization and the blocking temperature on the calcination temperature. The Co-based nanocomposites showed increased coercive field of the magnetic hysteresis loops relative to the other studied nanocomposites. It was also observed that the structural differences of the Cu-based composites subjected to calcination at two temperatures significantly modify the magnetic behavior. The catalytic properties of composites were tested in nitrous oxide decomposition. The conversion of nitrous oxide over the SiO2-MFe2O4 composites increased in the sequence: Mn (39%) < Ni (69%) < Co (76%) = Cu (76%), at temperature 973 K and WHSV = 30000 ml·g−1· h−1.

Cerium doped MgFe2O4 nanocomposites: highly sensitive and fast response-recoverable acetone gas sensor

We report a facile synthesis of Cerium doped MgFe2O4 nanocomposite ferrite and its usability as gas-sensor via simple and robust synthesis approach of glycine-combustion-process. The route utilizes metal nitrates (Ce, Mg, Fe -nitrates) and glycine, in aqueous solution. The involved sol-gel concept was explained on the basis of zwitterion characteristic of glycine. The analysis of the developed ferrite was done in two different ways – i) effect of Ce-doping concentration, and ii) effect of sintering temperature. With the ferrite system MgFe2-xCexO4, the doping concentration of Ce was varied from 0.04 to 0.12 with the step x = 0.04, and sintering was done at two different temperatures i.e. 973K and 1173K. As-produced composite system was examined for their gas response towards reducing gases such as LPG, ethanol, acetone and ammonia. The material displayed excellent gas sensing properties towards acetone for wide operating temperature range of 575–675 K. The XRD analysis revealed nanocrystallinity with crystallite size in the range of 28–34 nm. Microstructural analysis confirmed the porous morphology due to auto-ignition during the combustion reaction. The present investigations confirm the produced MgFe2-xCexO4 is a promising candidate for fabricating high performance acetone sensor.

Structural, morphological and optomagnetic properties of GO/Nd/Cu-Mn ferrite ternary nanocomposite

Graphene oxide (GO)/neodymium (Nd)/Cu 0·5 Mn 0·5 Fe 2 O 4 ternary nanocomposite was prepared by sonochemical method and modified Hummer's method. The crystal structure and structural parameter of Cu 0·5 Mn 0·5 Fe 2 O 4 (CMF) nanoferrites were changed with the addition of Nd 3+ and GO. Raman active modes of the GO and ferrite system were observed from Raman spectra. The surface oxidation state (C 1s, O 1s, Cu 2p, Mn 2p, Fe 2p, and Nd 3 d) and their respective binding energies of the prepared nanocomposite were discussed. Different surface morphologies were acquired for CMF, Cu 0·5 Mn 0·5 Fe 1.85 Nd 0.15 O 4 (CMNF), GO, and GO/Cu 0·5 Mn 0·5 Fe 1.85 Nd 0.15 O 4 (GCMNF) ferrite nanocomposites. The absorption of the Cu-Mn nanoferrite (red region) shifted into the blue region with the addition of Nd 3+ and GO. The magnetic parameters were changed with doping of Nd into CMF and GO in CMNF nanoferrite. It was found that the high anisotropy energy values of the CMNF and GCMNF ferrite nanocomposites could be used for electromagnetic wave-absorbing application.

Synthesis, characterization and antibacterial study of Ag doped magnesium ferrite nanocomposite

Nanomaterials are attracted a great deal of attention from scientific community due its unique properties and applications. The small size ferrites have opened up the door for intensive research to utilize their properties for biomedical applications. Ferrite nanomaterials like MgFe2O4 and its silver doped nanocomposites (Ag– MgFe2O4) have been prepared using solid state combustion method using polyvinyl alcohol (PVA) as a fuel. The structure of as prepared ferrites and its silver doped nanocomposites were characterized using X-ray diffraction (XRD) tool and morphology by Scanning Electron Micrograph (SEM) tool respectively. Presence of the metals in the ferrite and its composite was confirmed by EDX pattern. Bonding nature in the composite is well studied by Fourier transform infrared (FT-IR) tool. Antibacterial activity study of the nanocomposite is carried out against various bacteria. Ag doped magnesium ferrite shows moderate activity against bacteria.

Multifunctional nano-graphene based nanocomposites for multimodal imaging guided combined radioisotope therapy and chemotherapy

Multimodal imaging using nanomaterials in a single platform will bring hopeful for patients, and provide exact information including the tumor location and size for doctors. Herein, we synthesize reduced graphene oxide-manganese ferrite (RGO-MnFe2O4) nanocomposites via a hydrothermal reaction, and modify nanocomposites with polyethylene glycol (PEG) to improve its biocompatibility. Interestingly, PEGylated RGO-MnFe2O4 nanocomposites possess excellent T1/T2 weighted magnetic resonance imaging (MRI) of mice bearing 4T1 tumor after intravenous (i.v.) injection. After additional radioisotope labeling, SPECT imaging of 125I labeled RGO-MnFe2O4-PEG nanocomposites exhibit high tumor accumulation. Under the guidance of MRI/SPECT imaging, in vivo combined radioisotope therapy (RIT) and chemotherapy is carried out using anticancer drug doxorubicin and 131I co-loaded RGO-MnFe2O4-PEG nanocomposites, significant inhibiting the tumor growth after intravenous injection. Moreover, 131I- RGO-MnFe2O4-PEG/DOX nanocomposites cause no obvious toxicity to treated mice after 60 days post injection. Our study further promote the biomedical applications of nano-graphene based nanocomposites.

Magnetic investigation of microwave synthesized and thermal stable poly vinyl alcohol-cobalt ferrite nanocomposites

We synthesized CoFe2O4 nanoparticles using heating in various times by simple microwave method at power about 600W. Water, ethylene glycol and their combination were used as solvent. X-ray diffraction pattern(XRD) analysis was performed for evaluation of structural characterization of samples. We also used scanning electron microscopy (SEM) to evaluate the effects of various parameters of heating time and solvent type on mean grain size and nanostructure of the samples. Our results showed that with changing of these parameters, we can control the nanostructure and grain size of prepared samples. In addition, we produced polymeric nanocomposite of PVA/CoFe2O4 using poly vinyl alcohol films. The thermal stability of it in comparison to PVA polymer was assessed by thermal gravimetric analysis (TGA). Also the nanostructures of polymer nanocomposite were analyzed by SEM. To evaluate the magnetic parameters of samples, vibrating sample magnetometer (VSM) analysis were done. Also the spectrum of synthesized nanoparticles and polymer nanocomposite were drawn by FT-IR. Our results confirmed that the nanostructures, magnetic behavior and thermal stability of the prepared nanocomposite are acceptable for needed applications. Key Words: Cobalt ferrite nanoparticles, Magnetic behavior, Nanostructure, Polymer nanocomposite, Thermal stability

Interfacial exchange coupling driven magnetic and microwave properties of BaFe12O19/Ni0.5Zn0.5Fe2O4 nanocomposites

Exchange coupled hard/soft nanocomposite ferrites consist of BaFe12O19/ Ni0.5Zn0.5Fe2O4 (BaM/NZFO) in 70/30 wt ratio were prepared by sol–gel auto combustion method. Effect of annealing temperature (950 °C–1150 °C) on structural, magnetic and microwave properties have been investigated. The X-ray diffraction pattern confirms co-existence of both BaM and NZFO phases without any secondary phase. TEM micrographs showed well distinguished particles of BaM and NZFO with different symmetry. Saturation magnetization (Ms) increased from 58 emu/g to 65 emu/g with drastic decrease in coercivity (Hc). Higher Ms and low Hc than theoretical calculated values suggested that phases are well exchange coupled. A sharp Curie temperature (473 °C) for the composite was observed. The variation in Ms and Hc demonstrated that annealing temperature has strong influence on exchange coupling. Reflection losses in Ku-band were found to increase with a maximum value of −38 dB for the composite annealed at 1050 °C. Loss frequency also shifted toward lower values as a consequence of annealing temperature and exchange coupling.