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.

John Kennedy L

Physics

School of Advanced Sciences

Chennai Campus

Sundararajan M

Vijaya J.J

Aruldoss U.

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

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Strontium doped lanthanum cuprate perovskite-type nanostructures were synthesized by facile microwave assisted combustion method. The structural, optical, morphological, and magnetic properties were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), photoluminescence (PL) and vibrating sample magnetometer (VSM) techniques.The XRD patterns of pure La2CuO4 (LC) and La1.9Sr0.1CuO4 confirmed the formation of perovskite structure without impurities. However with the increase in Sr2+ content from (x = 0.2–0.5), phase transformation from orthorhombic to tetragonal structure, occurred. The average crystallite size of orthorhombic and tetragonal phases were in the range 39.6–47.4 nm and 22.3–88.0 nm, respectively. The presence of tensile strain in Sr2+ doped LC (LSC) was determined from Williamson–Hall (W–H) analysis. The appearance of FT-IR bands at around 688 and 521 cm-1 were correlated to the La-O and Cu-O stretching modes of orthorhombic La2CuO4 phase. The direct band gap estimated using Kubelka–Munk (K–M) method increased with increasing Sr2+ content (1.88–2.03 eV), due to quantum confinement. For LC and LSC, PL spectra showed emission bands in UV and visible regions, due to the defect centers acting as trap levels. The LSC system showed the formation of nanosized crystallized grains with pores and pore-walls due to fused grains. Magnetization–Field (M−H) hysteresis curves revealed the appearance of ferro-/para- magnetic behavior at room temperature. © 2018 Elsevier B.V.

Journal of Magnetism and Magnetic Materials

Facile microwave assisted combustion synthesis, structural, optical and magnetic properties of La2−Sr CuO4 (0 ≤ x ≤ 0.5) perovskite nanostructures

Co1-xCuxFe2O4 (0 ≤ x ≤ 0.5) nanoparticles were prepared by the microwave combustion technique. The obtained samples were characterized using X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray (EDX) analysis, UV-visible diffuse reflectance spectroscopy, photoluminescence (PL) spectroscopy, Fourier transformed infrared (FT-IR) spectroscopy and vibrating sample magnetometry. The XRD result confirms the formation of cubic spinel structure and the average crystallite size was observed to be in the range of 46-31 nm calculated by Debye Scherrer's equation. XPS analysis was carried out to study the chemical elements and oxidation states of the synthesized Co1-xCuxFe2O4 (0 ≤ x ≤ 0.5) nanoparticles. The HR-SEM image showed agglomerated spherical nanoparticles and the elemental composition of copper doped cobalt ferrite was attained from energy dispersive X-ray analysis. The band gap energy was calculated by diffuse reflectance spectroscopy. Photoluminescence spectra showed the rate of recombination of electron-hole pairs and presence of defects. The band at 661 and 569 cm-1 is due to the intrinsic stretching vibrations of octahedral group complex of Co2+-O2- and Fe3+-O2- at tetrahedral sites. Remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms) were deduced from the hysteresis curves. The obtained Co1-xCuxFe2O4 (0 ≤ x ≤ 0.5) nanoparticles were assessed for the photocatalytic degradation of RhB under visible light. A possible mechanism responsible for photocatalytic degradation process is discussed. © 2017 Elsevier Ltd. All rights reserved.

Journal of Environmental Chemical Engineering

Photocatalytic removal of rhodamine B under irradiation of visible light using Co1Cu Fe2O4 (0 ≤x≤ 0.5) nanoparticles

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.

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

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

Co1-xMgxFe2O4 (0≤x≤0.5) spinel nanoparticles were synthesized by a simple microwave combustion method. The characterization of the samples were performed using X-ray diffraction (XRD) analysis, scanning electron (SEM) microscopy, energy dispersive X-ray (EDX) analysis, UV–visible and diffuse reflectance (DRS) spectroscopy, photoluminescence (PL) spectroscopy, Fourier transformed infrared (FT-IR) spectroscopy and vibrating sample magnetometry (VSM) analysis. The XRD patterns indicate the formation of cubic inverse spinel structure. The calculated average crystallite size using Debye Scherrer's equation is found to be around 46–38 nm. The morphology of spinel nanoparticles was observed from SEM images and the elemental mapping of magnesium doped cobalt ferrite was obtained by using energy dispersive X-ray technique. Optical studies were carried out for the deeper understanding of the conduction band (CB) and valence band (VB) edges of the synthesized nanoparticles. The intrinsic stretching vibrations of Fe3+-O2- in tetrahedral sites leads to the appearance of IR band at around 573 cm−1. The magnetic properties such as remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms) were calculated from the hysteresis curves. The maximum photocatalytic degradation efficiency for Co0.6Mg0.4Fe2O4 is around (99.5%) when compared to that of CoFe2O4 whose efficiency is around (73.0%). The improvement in photocatalytic degradation efficiency is due to the effective separation and prevention of electron-hole pair recombination. The R2 values for the first order rate kinetics are found to be better than R2 values for the second order rate kinetics and this proves that photocatalytic degradation of RhB dye follows first order kinetics. The probable mechanism for the photocatalytic degradation of RhB dye is proposed. © 2017 Elsevier Ltd

Journal of Physics and Chemistry of Solids

Visible light driven photocatalytic degradation of rhodamine B using Mg doped cobalt ferrite spinel nanoparticles synthesized by microwave combustion method

FTIR and UV–vis diffuse reflectance spectroscopy studies of the wet chemical (WC) route synthesized nano-structure CoFe2O4 from CoCl2 and FeCl3

Synthesis, structural investigation and magnetic properties of Zn2+ substituted cobalt ferrite nanoparticles prepared by the sol–gel auto-combustion technique

Ceramics International

Developments of cobalt ferrite nanoparticles prepared by the sol–gel process

Journal of Alloys and Compounds

Structural, magnetic and dielectric properties of Pr-modified BiFeO3 multiferroic

Journal of Molecular Structure

Structural and magnetic properties of Co–Al substituted Ni ferrites synthesized by co-precipitation method

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

Journal	Data powered by TypesetSpectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publisher	Data powered by TypesetElsevier BV
ISSN	1386-1425
Open Access	0