Recent developments show that the exceptional physical, optical, magnetic, and electrical properties of spinel ferrite (SF) nanomaterials have now attracted the attention as high-density data storage materials, catalysts, gas sensors, rechargeable lithium batteries, information storage systems, magnetic bulk cores, adsorbents, magnetic fluids, microwave absorbers, and medical diagnostics. The aim of this review consists on an overview on the methods of preparation, the crystal structure and application of SFs used in technology for the design of new materials and devices. The chapter begins with a review of the different synthesis methods commonly used for the preparation of SFs. Then, the structural features of spinel unit cell, crystal chemical parameters, and extrinsic magnetic and optical properties are described in this chapter. Since the magnetism of SFs depends not only on particle chemistry and phase but also on the particle size and environment, the role of cationic distribution and ion exchange interaction are explored in determining the magnetic properties of the system. In addition, the potential applications of SFs in different fields of technology are also discussed. © Springer International Publishing AG 2017.

John Kennedy L

Physics

School of Advanced Sciences

Chennai Campus

Tatarchuk T

Bououdina M

Judith Vijaya J

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Spinel Ferrite Nanoparticles: Synthesis, Crystal Structure, Properties, and Perspective Applications

Springer Proceedings in Physics Nanophysics, Nanomaterials, Interface Studies, and Applications

In the present work, zinc ferrite nanostructured materials were synthesized by a microwave combustion method (MCM) using Okra (Abelmoschus esculentus) as a plant extract and compared with the ones synthesized by a conventional combustion method (CCM). Plant extracts play a dual role of both oxidizing and reducing nature. Microwave assisted combustion method is a potential, attractive and energy saving technique when compared to conventional heating, due to the direct heating of the reaction mixtures. They have several advantages, such as, simple, inexpensive, good stability of nanoparticles, less time consumption, and large-scale synthesis. The synthesized products are investigated by the standard characterization techniques, such as, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), Rietveld refinement analysis, high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), photoluminescence studies (PL), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM), for the structural phase, morphology, optical and magnetic properties. The development of the single cubic phase ZnFe2O4 is affirmed by XRD and FT-IR. The morphological studies of the obtained ZnFe2O4 nanoparticles were investigated by HR-SEM studies. The optical band gap value was determined by DRS. The change in saturation magnetization (Ms) and coercivity (Hc) was observed by VSM studies. Dye Sensitized Solar Cell made up of ZnFe2O4 nanoparticles prepared by microwave method exhibited maximum conversion efficiency of around 0.22%, which is higher than that obtained from conventional combustion method gave efficiency of approximately 0.15%. © 2016 Elsevier GmbH

Optik

Optical, magnetic and structural properties of ZnFe2O4 nanoparticles synthesized by conventional and microwave assisted combustion method: A comparative investigation

Nanostructured Co1-xZnxFe2O4 (0≤x≤0.5) catalyst synthesized by the microwave combustion method was employed for the photocatalytic degradation of rhodamine B (RhB) under visible light. Doping of Zn2+ ions in the cobalt ferrite matrices were confirmed by the diffraction peak-shift towards lower angles. The Williamson-Hall method was used to calculate the crystallite size considering the strain components. The conduction band (CB) and valence band (VB) edges of all the samples were calculated using optical studies. Photoluminescence analysis performed at an excitation wavelength of 330 nm disclosed the rate of recombination of electron-hole pairs and the defects present. Photocatalytic degradation of RhB with pure cobalt ferrite system was performed at pH 2.0 by varying the time, initial concentration and addition of hydrogen peroxide to behave like a Fenton like process. However the effective photodegradation of all zinc doped cobalt ferrite were done at optimal RhB concentration of 6 mg/l at identical operational conditions. Among all the samples Co0.6Zn0.4Fe2O4 exhibited an enhanced degradation efficiency of 99.9% at visible light exposure time of 210 min. The degradation pathway followed first order rate rather than the second order rate kinetics. Based on the values of CB and VB edges in the Co0.6Zn0.4Fe2O4 system, possible routes for the degradation of RhB are suggested. © 2016 Elsevier Ltd and Techna Group S.r.l.

Ceramics International

Photocatalytic degradation of rhodamine B under visible light using nanostructured zinc doped cobalt ferrite: Kinetics and mechanism

The present work describes the successful synthesize of spinel magnetic ferrite Mn1-xNixFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 &amp; 0.5) nanoparticles via a simple microwave combustion method which was then evaluated for its photocatalytic activity in the degradation of indigo carmine (IC) synthetic dye, a major water pollutant. Our results reveal that the synthesized of Ni2+ doped MnFe2O4 nanoparticles possess well-crystalline pure cubic spinel phase, exhibit excellent optical and magnetic properties. Further, the photocatalytic performance of the synthesized nanoparticles at different concentration ratios of Ni2+ ions was monitored by photocatalytic degradation of indigo carmine synthetic dye under UV (λ = 365 nm) light irradiation. In order to get maximum photocatalytic degradation (PCD) efficiency, we have optimized various parameters, which include catalyst dosage, initial dye concentration, pH and Ni2+ dopant content. It was found that the reaction was facilitated with optimum catalyst dose of 50 mg/100 mL, high dye concentrations of 150 mg/L and acidic pH and among all the synthesized samples, Mn0·5Ni0.5Fe2O4 exhibit superior performance of photocatalytic activity on the degradation of indigo carmine synthetic dye. These results highlighted the potential use of effective, low-cost and easily available photocatalysts for the promotion of wastewater treatment and environmental remediation. In addition, the antibacterial activity of spinel magnetic Mn1–xNixFe2O4 nanoparticles against two Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli) was also examined. Our antibacterial activity results are comparable with the results obtained using the antibiotic, streptomycin. © 2016 Elsevier B.V.

Journal of Photochemistry and Photobiology B: Biology

Studies on the efficient dual performance of Mn1–xNixFe2O4 spinel nanoparticles in photodegradation and antibacterial activity

Nanostructured pure and zinc doped cobalt ferrites (Co1-xZnxFe2O4 where x fraction ranging from 0 to 0.5) were prepared by microwave combustion method employing urea as a fuel. The nanostructured samples were characterized by using various instrumental techniques such as X-ray powder diffractometry, high resolution scanning electron microscopy, energy dispersive X-ray analysis, UV-visible diffuse reflectance spectroscopy, photoluminescence spectroscopy and Fourier transformed infrared (FT-IR) spectroscopy. Vibrating sample magnetometry at room temperature was recorded to study the magnetic behavior of the samples. X-ray analysis and the FT-IR spectroscopy revealed the formation of cobalt ferrite cubic spinel-type structure. The average crystallite sizes for the samples were in the range of 3.07-11.30 nm. The direct band gap (Eg) was estimated using Kubelka-Munk method and is obtained from the UV-vis spectra. The band gap value decreased with an increase in zinc fraction (2.56-2.17 eV). The violet and green emission observed in the photoluminescence spectra revealed that cobalt ferrites are governed by defect controlled processes. The elemental analysis of zinc doped cobalt ferrites were obtained from energy dispersive X-ray (EDX) analysis. From the magnetic measurements, it is observed that cobalt ferrite and zinc doped cobalt ferrite systems fall under the soft ferrite category. The saturation magnetization (Ms) value of undoped cobalt ferrite is 14.26 emu/g, and it has reached a maximum of 29.61 emu/g for Co0.7Zn0.3Fe2O4. © 2014 Elsevier B.V. All rights reserved.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Microwave combustion synthesis of Co1−xZnxFe2O4 (0⩽x⩽0.5): Structural, magnetic, optical and vibrational spectroscopic studies

Iron oxide (Fe3O4) nanoparticles were synthesized by a facile microwave combustion method. X-ray diffraction and energy dispersive X-ray spectroscopy results showed that the as-prepared product was pure Fe3O4 without any impurity. The mechanism for the formation of Fe3O4 by microwave combustion method is also discussed. Microwave combustion produced sufficient energy for the formation of Fe3O4, because of its homogeneous distribution within the raw materials. This results in the formation of nanoparticles, early phase formation and different morphologies within few minutes. Magnetic analysis revealed that the Fe3O4 nanoparticles had ferromagnetic behavior at room temperature with saturation magnetization of 66.12 emu/g. © 2013 The Korean Society of Industrial and Engineering Chemistry.

Journal	Data powered by TypesetSpringer Proceedings in Physics Nanophysics, Nanomaterials, Interface Studies, and Applications
Publisher	Data powered by TypesetSpringer International Publishing
ISSN	0930-8989
Open Access	No