Structural and Magnetic Properties of Manganese Zinc Ferrite Nanoparticles Prepared by Solution Combustion Method Using Mixture of Fuels

The structural analysis and magnetic investigation Mn1−xZnxFe2O4 with stoichiometry (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by solution combustion method using mixture of fuel this is first of its kind. As synthesized Mn–Zn nanoferrites were characterized by X-ray Diffractometer (XRD), Transmission electron microscopy (TEM) at room temperature. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (fr) was increased with the increase in grain size. The Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM). It was observed that the real and imaginary part of permeability (µ' and µ?), saturation magnetization (Ms), remanance magnetization (Mr) and magneton number (Mr/Ms) were decreases gradually with increasing Zn2+ concentration. The decrease in the saturation magnetization may be explained as, the Zn2+ concentration increases the relative number of ferric ions on the A sites diminishes and this reduces the A–B interaction. Hence synthesized materials are good for high frequency applications

Effect of Sm3+-Gd3+ on structural, electrical and magnetic properties of Mn-Zn ferrites synthesized via combustion route

Nanocrystalline Mn0.4 Zn0.6 SmxGdyFe2-(x+y)O4 (x = y = 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by combustion route. The detailed structural studies were carried out through X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM). The results confirms the formation of mixed spine phase with cubic structure due to the distortion created with co-dopants substitution at Fe site in Mn-Zn ferrite lattice. Further, the crystallite size increases with an increase of Sm3+-Gd3+ ions concentration while lattice parameter and lattice strain decreases. Furthermore, the effect of Sm-Gd co-doping in Mn-Zn ferrite on the room temperature electrical (dielectric studies) studies were carried out in the wide frequency range 1 GHz-5 GHz. The magnetic studies were carried out using vibrating sample magnetometer (VSM) under applied magnetic field of 1.5T and also room temperature electron paramagnetic resonance (EPR) spectra's were recorded. From the results of dielectric studies, it shows that the real and imaginary part of permittivities are increasing with variation of Gd3+ and Sm3+ concentration. The magnetic studies reveal the decrease of remnant, saturation magnetization and coercivity with increasing of Sm3+-Gd3+ ion concentration. The g-value, peak-to-peak line width and spin concentration evaluated from EPR spectra correlated with cations occupancy. The electromagnetic properties clearly indicate that these materials are the good candidates which are useful at L and C band frequency. © 2015 Elsevier B.V

Investigation of Structural, Microstructural, Dielectrical and Magnetic Properties of Bi3+ Doped Manganese Spinel Ferrite Nanoparticles for Photonic Applications

The structural, microstructural, and magnetic properties of Mn1-xBixFe2O4 (where x = 0.0, 0.05, 0.1, 0.15, and 0.2) nanoparticles prepared by solution combustion method were investigated. Rietveld-refined X-ray diffraction patterns confirm the single-phase formation with space group Fd3m having spinel cubic structure. The porous nature of the samples was confirmed by scanning electron microscopy (SEM). Composition values of the theoretical stoichiometry and energy-dispersive spectroscopy (EDS) composition values are well matched for all samples. The dielectric parameters such as real part of dielectric constant, imaginary part of dielectric constant, and dielectric loss tangent decrease with the increase in frequency. The AC conductivity increases with increase in the Bi3+ concentration. The real part of complex impedance decreases with the increase in frequency. Cole-Cole plots reveal that one semicircle was obtained for each of the samples. The real and imaginary parts of electric modulus vary with frequency. The magnetic hysteresis curves of all samples reveal the soft magnetic material nature. We observed S esteems began uniquely from the higher superparamagnetic, we would have watched the monotonic decrease in S with increase in Bi3+ concentration. Furthermore, the magnetic parameters were estimated

Effect of Sm3+ substitution on structural and magnetic investigation of nano sized Mn-​Sm-​Zn ferrites

Nano size Mn0.4Zn0.6SmxFe2-​xO4 (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05) ferrites were prepd. by soln. combustion method. The structural and magnetic properties of samples were characterised by X-​ray diffractometer, Fourier transform IR spectrometer, transmission electron micrographs and magnetic properties at room temp. The X-​ray diffraction patterns and two prominent absorption bands in the frequency range 375-​589 cm-​1 confirmed the single phase with spinel cubic structure. The av. nano crystallite sizes were in best agreements with transmission electron microscope images. Magnetic studies revealed the narrow hysteresis loops of ferrimagnetic nature at room temp. The values of satn. magnetization (Ms)​, remanence magnetization (Mr)​, coercivity (Hc)​, remanence ratio (Mr/Ms)​, magneton no., anisotropy const. and Yaffet-​Kittle angle decreased with the increase in Sm3+ ion concn. was attributed to relative no. of ferric ions on the tetrahedral sites diminished and reduced the Sm-​Fe interaction

Low temperature Mössbauer spectroscopic studies on Sm3+ doped Zn-Mn ferrites

For the first time, we report on the low temperature Mössbauer spectroscopic study of Zn2+ 0.5Mn2+ 0.5Sm3+ xFe3+ 2�xO4 (where x = 0.01�0.05) prepared by the modified solution combustion method using a mixture of urea and glucose as a fuel. The Mössbauer spectroscopy at room and low temperatures was applied to understand the magnetic properties of the samples. The room temperature Mössbauer spectroscopy results suggest that the occupation of the octahedral sites by Sm3+ ions leads to the distortion enhancement of 57Fe nuclei environments, which leads to an increase in quadrupole splitting � values of D2 and D3 doublets. The low temperature Mössbauer spectroscopy results indicate that the presence of Sm3+ ions in the octahedron sites causes the decrease in the number of Fe�O�Fe chains. The transformation of Mössbauer spectra doublets into Zeeman sextets is accompanied by a significant decrease in the magnitude IM of Mössbauer spectra intensity within the 0�1.2 mm/s velocity range normalized to its value at 300 K. This drop in the temperature dependence of IM allows one to obtain the magnetic phase transition temperature TM from the Mössbauer experiment. © 2017 Elsevier B.V

Enhanced Humidity Sensing Response in Eu³⁺-Doped Iron-Rich CuFe₂O₄: A Detailed Study of Structural, Microstructural, Sensing, and Dielectric Properties

The CuFe(2−x)EuxO4 (where x = 0.00, 0.01, 0.02, 0.03) nanoparticles are synthesized by solution combustion method. The influence of Eu3+ on the structural, morphological, dielectrical, and humidity sensing study is recorded. The XRD pattern peaks of the as-prepared CuFe(2−x)EuxO4 (where x = 0.00, 0.01, 0.02, 0.03) nanoparticle confirm the polycrystalline spinel cubic structure with a small amount of CuO impurity phase at 38.87° and 48.96°. Surface morphology of the samples was studied by scanning electron microscope (SEM) images of the nanoparticles, and their respective average grain size was estimated using Image software. Chemical composition of all prepared samples was analyzed by EDS spectra. The dielectric parameters of AC conductivity, electric modulus, and impedance of the samples were measured over a range of frequencies from 0.1 KHz to 1 MHz at room temperature. Europium-doped copper ferrite samples showed good humidity sensing response, response and recover times, and stability over a %RH range of 11–91%. These types of samples are very useful for sensor application, battery applications, electronic applications, and automotive applications

Effect of Ce3+ Ion on Structural and Hyperfine Interaction Studies of Co0.5Ni0.5Fe2−xCexO4 Ferrites: Useful for Permanent Magnet Applications

Abstract Nanoparticles of Co0.5Ni0.5Fe2−xCexO4 (where x = 0.0, 0.01, 0.015 and 0.02) ferrites are prepared by the modified solution combustion method using a mixture of fuels and are characterized to understand their structural, microstructural and magnetic properties. The X-ray diffraction is used to confirm the formation of a single-phase cubic spinel structure. The average crystallite sizes are calculated using the Scherrer formula and are found to be less than 50 nm. The microstructural features are obtained by the scanning electron microscopy, and the compositional analysis is done by using the energy-dispersive spectroscopy. The transmission electron microscopy (TEM) investigations show that the synthesized ferrites are made up of very fine spherical nanoparticles. The influence of a rare-earth element (Ce3+) on the magnetic properties of the samples was studied using the Mössbauer spectroscopy. The Mössbauer spectroscopy reveals the formation of broadened Zeeman lines and quadrupole-split lines and the presence of the Fe3+ charge state at B sites in the samples. The quadrupole splitting shows that the orientation of the magnetic hyperfine field with respect to the principle axes of the electric field gradient was random. The magnetic hyperfine field values indicate that the A sites have more A-O-B superexchange interactions than the B sites. The coexistence of magnetic sextet and a doublet component on the room-temperature spectra suggests superparamagnetic properties of the nanoparticles. The low-temperature (15 K) Mössbauer spectroscopy explores the paramagnetic relaxation in the nanoparticles. The area under the sextet refers to Fe3+ concentrations in the tetrahedral and octahedral sites of the ferrite. This study confirms that the Ce3+ substitution of Fe3+ only for octahedron sites causes the decrease in Fe-O-Fe arrangement. The effect of Ce3+ doping on the magnetic properties of Co0.5Ni0.5Fe2O4 is examined from the vibrating sample magnetometry (VSM) spectra. Saturation magnetization values are decreased initially and then increased, as result of Ce3+ doping. This can be explained by Neel’s two-sub-lattice model. Further, the value of coercivity is found to be increasing with increasing Ce3+ concentration. The obtained results of M-H loop with improved coercivity (from 851 to 1039 Oe) by Ce3+ doping of Co0.5Ni0.5Fe2O4 demonstrate the usefulness for permanent magnet applications

Synthesis and study of Structural, Microstructural and Dielectric Properties of Ce3+ doped Co-Ni Ferrites for automotive applications

Nano crystalline spinel ferrites of Co0.5Ni0.5CexFe2−xO4 (x=0.01, 0.015, 0.02, 0.025 and 0.03) was prepared by modified solution combustion method using a mixture of fuels for the first time. The influence of rare earth Ce3+ substitution at the Fe3+ site on the structural, microstructural and dielectric properties of Co0.5Ni0.5CexFe2-xO4 was investigated. The X-ray diffraction (XRD) studies confirmed the formation of monophasic nano crystalline samples without any secondary phases. The crystallite size decreases and density increases with the increases of Ce3+ contents. Surface morphology was studied through Scanning Electron Microscopy (SEM). Dielectric properties of these ferrites have been studied at room temperature using impedance analyzer in the frequency range up to 20 MHz. The effect of frequency and composition on dielectric constant (ε’), dielectric loss (tanδ) and ac conductivity (σac) have been discussed in terms of hopping of charge carriers (Fe2+↔Fe3+). The decrease in dielectric loss with frequency follows Debye's relaxation phenomena. Both the variation in tan loss and dielectric loss with frequency shows a similar. AC conductivity increases with the increases of frequency which directly proportional to concentration of Ce3+ ions follows Jonscher law. These Cerium doped Cobalt-nickel ferrites are very helpful for automotive applications