EFFECT OF MULTIWALLED CARBON NANOTUBES ON Co-Mn FERRITE PREPARED BY CO-PRECIPITATION TECHNIQUE (original) (raw)
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Nano sized Mn0.5Zn0.5Fe2O4 ferrite particles were synthesized by co-precipitation method. The composite of Mn0.5Zn0.5Fe2O4 and multiwalled carbon nanotube have been successfully formed by the solid state reaction method. Multiwalled carbon nanotubes (MWCNTs) are substituted in the soft ferrite Mn0.5Zn0.5Fe2O4, with weight percent ratio of 1%, 5% and 9%. The effect of MWCNTs on the Structural, Thermal and Magnetic properties of Mn-Zn ferrites is reported. The X-ray diffraction analysis of sintered powder 1000C reveals the ferrite possesses spinel face centered cubic structure. Structural, Thermal analysis of the MWCNTs and Mn-Zn ferrite composite are characterized by XRD, SEM and TGA/DSC techniques. Particle size is observed by SEM ranging from 25nm to 40nm. The magnetic properties are measured by using the Physical property measurements (PPMS) technique. The Fourier transform infrared spectroscopy is used to detect the presence of the metallic compounds in the ferrite sample. The s...
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Nanoparticles of Co1−xZnxFe2−xCrxO4 (x = 0.0–0.5) ferrites were prepared by chemical co-precipitation technique using metal sulphates. The structural and magnetic properties were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and AC susceptibility measurements. X-ray diffraction patterns indicate that the samples possess single phase cubic spinel structure. The lattice constant initially increases for x ≤ 0.3 and thereafter for x > 0.3 it decreases with increasing x. The saturation magnetization (Ms), magneton number (nB) and coercivity (Hc) decreases with increasing Cr–Zn content x. Curie temperature deduced from AC susceptibility data decreases with increasing x.► Preparation of nanostructured ferrite particles. ► Co-substitution of Zn2+ and Cr3+ in place of Co2+ and Fe3+ ions. ► Structural properties markedly vary with increasing Cr–Zn ions. ► Magnetic properties decrease with increasing Cr–Zn ions.
Influence of temperature on structural and magnetic properties of Co0⋅5Mn0⋅5Fe2O4 ferrites
Co 0⋅5 Mn 0⋅5 Fe 2 O 4 ferrites have been synthesized using a single-step sol-gel auto-combustion method in which the metal nitrate (MN)-to-citric acid (CA) ratio was adjusted to 0⋅5 : 1 and pH to 7, respectively. The structural and magnetic properties of as-burnt and annealed samples were studied as a function of temperature. The inverse spinel structure was confirmed by X-ray diffraction (XRD) and crystallite size was estimated by the most intense peak (311) using Scherrer's formula. Contrary to earlier studies reported in the literature, both as-burnt and annealed samples exhibit crystalline behaviour. Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM) with field strengths up to ± 10 kOe. Lattice constant and crystallite size increased as the annealing temperature was increased. However, the coercivity (H c ) initially increased and then decreased with the increase of crystallite size. The variation in coercivity is ascribed to the transition from a multi-domain to a single-domain configuration. Figure 6. Variation of coercivity with annealing temperature.
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Synthesis and Characterization of Co-Substituted Ferrite Nanocomposites
IEEE Transactions on Magnetics, 2000
Fe O (where x is 0, 0.25, 0.50, 0.75, 1) nanoparticles (NPs) by a wet chemical method using carboxymethyl cellulose (CMC) solution as surfactant. Their structure and magnetic properties were evaluated by X-ray diffraction (XRD), Fourier-Transform Infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). The gas and humidity sensing properties of the samples were also investigated. Powder X-ray diffraction analysis demonstrated the formation of face-centered cubic structure for all the samples. The average crystallite size and lattice parameters have been calculated by Rietveld refinement. The FTIR spectra of NPs confirm the presence of CMC functional groups and stretching bands attributed to the intrinsic vibrations of tetrahedral and octahedral sites of spinel ferrite. The magnetization curves of the nanocomposites at room temperature demonstrated saturation magnetizations from 21 emu/g to 58 emu/g and coercivity values between 130 Oe and 835 Oe. As not many studies have been published on this topic, the gas sensing properties of Ni-substituted Co ferrites have been evaluated. The measurements revealed that Co Ni Fe O is the most sensitive to acetone vapors.
Journal of Alloys and Compounds, 2009
Magnetic particles of nanocrystalline cobalt ferrite has been synthesized successfully by polymeric precursor method and the influence of the calcination temperature on the particle sizes and magnetic properties of the synthesized samples have been also investigated. The particles have been calcined at different temperatures varying from 400 to 800 • C. The studies carried out using XRD, FT-IR, SEM, TEM, STA (TG-DTG-DTA) and VSM techniques. The results indicated that the ferrite samples obtained by this method had the nanocrystalline pure single-phase spinel structure and good magnetic properties. TEM images showed almost spherical nanoparticles which are uniform in both morphology and particle size distribution with sizes varied in the range of 13-145 nm with the calcination temperature. The gradual increase in the crystallite size with the calcination temperature indicates the formation of bigger particles on the calcination. Magnetic properties of the products were found greatly affected by the average crystalline size of the nanoparticles. The saturation magnetization and remanent magnetization values of the samples increased as a function of the calcination temperature. Our results showed this method facilitates the magnetic tunability of the Co-ferrite nanoparticles by using the proper temperature of the thermal treatment and greatly expanding the range of applications.
Cu2+ and Al3+ co-substituted cobalt ferrite: structural analysis, morphology and magnetic properties
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Cu-Al substituted Co ferrite nanopowders, Co 1−x Cu x Fe 2−x Al x O 4 (0.0 ≤ x ≤ 0.8) were synthesized by the co-precipitation method. The effect of Cu-Al substitution on the structural and magnetic properties have been investigated. X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) are used for studying the effect of variation in the Cu-Al substitution and its impact on particle size, magnetic properties such as M s and H c. Cu-Al substitution occurs and produce a secondary phase, α-Fe 2 O 3. The crystallite size of the powder calcined at 800 • C was in the range of 19-26 nm. The lattice parameter decreases with increasing Cu-Al content. The nanostructural features were examined by FESEM images. Infrared absorption (IR) spectra shows two vibrational bands; at around 600 (v 1) and 400 cm −1 (v 2). They are attributed to the tetrahedral and octahedral group complexes of the spinel lattice, respectively. It was found that the physical and magnetic properties have changed with Cu-Al contents. The saturation magnetization decreases with the increase in Cu-Al substitution. The reduction of coercive force, saturation magnetization and magnetic moments are may be due to dilution of the magnetic interaction.
Materials Research Bulletin, 2014
A series of Co 2+ doped Mn-Zn ferrite ceramics with the formula Mn 0.5 Zn 0.5-x Co x Fe 2 O 4 (x = 0, 0.25 and 0.50) have been successfully synthesized using polyethylene glycol-assisted coprecipitation and hydrothermal methods. The structural characterization of the samples has been done using room temperature X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD patterns revealed the formation of pure FCC spinel phase without any impurity peaks. SEM showed the uniform, homogenously spherical nanoparticles prepared from controlled reaction of hydrothermal method. Lattice constant found to be smaller for samples prepared from hydrothermal treatment. The average crystallite size of all nanoparticles were estimated using Scherrer's formula and found to lie between 10 -25 ± 3 nm with small size distribution of particles prepared by hydrothermal method. Bond length (A-O) and ionic radii (r A ) at A-sites are smaller than the bond length (B-O) and ionic radii (r B ) at B-sites for sample series prepared by two methods. Magnetic properties were studied using physical property measurement system (PPMS), Quantum Design vibrating sample magnetometer (VSM) option. Magnetic properties including saturation magnetization was higher (65emu/g for x = 0.25) for hydrothermal treated samples. The method of preparation influenced the size of particle which in turn has strong affect on magnetic properties of prepared samples. The enhanced magnetic and structural properties of these nano ferrites made them a potential candidate to use in electromagnetic devices.
Malaysian Journal of Fundamental and Applied Sciences, 2015
This study evaluates the morphology and structural properties of Ni-Mg substituted Cobalt ferrite samples prepared through the co-precipitation method. The nominal composition of Co0.5Ni0.4Mg0.1Fe2O4 has been synthesized and then was sintered at 700 and 1000°C for 10 hour with a heating rate of 5°C/min. The prepared nano-ferrites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 40-120 nm. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.