Nickel Zinc Ferrite Nanoparticles Research Articles

Morphology and dielectric properties of single sample Ni0.5Zn0.5Fe2O4 nanoparticles prepared via mechanical alloying

Nickel-zinc ferrite nanoparticles are important soft magnetic materials for high and low frequency device application and good dielectric materials. Nickel-zinc ferrite nanoparticles with composition Ni0.5Zn0.5Fe2O4 were prepared using mechanical alloying to analyze the effect of sintering temperature on microstructure evolution of a single sample with dielectric properties. The single sample with nanosized pellet was sintered from 600 °C to 1200 °C and analyzed by X-ray diffraction (XRD) to investigate the phases of the powders and by field emission scanning electron microscopy (FESEM) for the morphology and microstructure analyses. Dielectric properties such as dielectric constant (ɛ′) and dielectric loss (ɛ″) were studied as functions of frequency and temperature for Ni0.5Zn0.5Fe2O4. The dielectric properties of the sample were measured using HP 4192A LF impedance analyzer in the low frequency range from 40 Hz to 1 MHz and at temperature ranging from 30 °C to 250 °C. The results showed that single phase Ni0.5Zn0.5Fe2O4 cannot be formed by milling alone and therefore requires sintering. The crystallization of the ferrite sample increased with increasing sintering temperature, while the porosity decreased and the density and average grain size increased. Evolution of the microstructure resulted in three activation energies of grain growth, where above 850 °C there was a rapid grain growth in the microstructure. Dielectric constant and loss factor decreased with the increase in frequency. The optimum sintering temperature of Ni0.5Zn0.5Fe2O4 was found to be 900 °C which had high dielectric constant and low dielectric loss.

Morphology and Mechanical Properties of NiZn Ferrite/Thermoplastic Natural Rubber Composite

In this paper the polymer nanocomposite of nickel zinc (NiZn) ferrite nanoparticles incorporated into the thermoplastic natural rubber nanocomposite (TPNR) were prepared via melt blending method. The effect of different NiZn loading (2-10 wt%) on morphology, tensile and dynamic mechanical properties of the obtained composites was investigated. It was found that NiZn ferrite is well dispersed in the thermoplastic natural rubber matrix. The tensile results indicated that filler loading has improved the tensile strength and Youngs modulus of the nanocomposite. However, the elongation at break decreased with increasing the percentage of NiZn. Dynamic mechanical test showed that the highest storage modulus is at 8 wt% filler. Any further increment of the filler content leads to the formation of agglomerate hence affecting the properties. The Scanning electron micrograph (SEM) micrographs reveal aspect ratio and filler orientation in the TPNR matrix also strongly promoted interfacial adhesion between the filler and the matrix to control its properties.

Effect of Copper Substitution on Structural and Magnetic Properties of NiZn Ferrite Nanopowders

In this study, nickel-zinc ferrite nanoparticles, with the chemical formula of <TEX>$Ni_{0.3}Zn_{0.7-x}Cu_xFe_2O_4$</TEX> (where x = 0.1- 0.6 by step 0.1), were fabricated by the sol-gel method. The effect of copper substitution on the phase formation and crystal structure of the sample was investigated by X-ray diffraction (XRD), thermo-gravimetry (TG), differential thermal analysis (DTA), Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD result shows that due to the reduction of Zn content,the crystallite size of the sample increased. The results of the vibration sample magnetometer (VSM) exhibit an increase in saturation magnetization value (Ms) for samples with x <TEX>${\leq}$</TEX> 0.3 and a linear decrease for samples with x > 0.3. The variation of saturation magnetization and coercivity of the samples were then studied.

Mechanical and thermomechanical properties of radiation modified poly(ethylene-octene)/Ni-Zn ferrite nanocomposites

Poly(ethylene-1-octene) copolymer (POE) composites filled with nickel-zinc ferrite nanoparticles have been modified by exposure to an electron beam at doses up to 500 kGy. The influence of radiation dose and ferrite content on mechanical properties has been investigated. Thermomechanical properties – thermorelaxation stresses formed in thermal heating and thermo residual stresses resulting in the process of full setting and cooling of materials have been investigated for radiation cross-linked oriented (extended up to 100%) composite samples. Increase of concentration of ferrite particles and increase of radiation dose affects a notable increase of elastic modulus and reduces the deformability in comparison to entire elastomer. Improvement of thermomechanical properties especially at low irradiation doses (100–150 kGy) have been detected for composites with increase of ferrite filler content up to 5 wt. %. It was found that gel content of POE increased up to 85% for pristine POE material with increase of irradiation dose up to 500 kGy due to the formation of cross-linked structure, increase of filler concentration up to 5 wt. % affect reduction in gel fraction due to uniform dispersion in amorphous (ethylene and substituted with hexyl branches) POE phases.

Synthesis and Magnetic Behavior of Nickel Zinc Ferrite Nanoparticles Coated Onto Carbon Microcoils

Magnetic nanoparticles consisted of nickel zinc ferrite (NZF) were chemically synthesized by co-precipitation and simultaneously coated onto carbon microcoils (CMC), and their structure and magnetic properties were investigated. The samples were prepared at various mass ratios of CMC : NZF ranging from 1 : 5 to 5 : 1. According to X-ray diffraction (XRD) measurements, all the samples synthesized in this study exhibit peaks associated with the spinel ferrite structure of NZF nanoparticles along with a fairly broad peak due to the amorphous structure of CMC. The sample synthesized at CMC: NZF = 1 : 1 gives the highest crystallinity and the largest magnetization at 300 K for NZF according to XRD and magnetization measurement using a superconducting quantum interference device magnetometer. Microstructural analysis of the CMC-NZF assemblies using scanning electron microscopy shows that the use of oleic acid and oleylamine improves the coverage of NZF on CMC and that the assembly made at CMC: NZF = 2 : 1 yields the highest coverage of NZF nanoparticles onto the CMC surface.

Effect of preparation conditions on Nickel Zinc Ferrite nanoparticles: A comparison between sol–gel auto combustion and co-precipitation methods

The experimental conditions used in the preparation of nano crystalline mixed ferrite materials play an important role in the particle size of the product. In the present work a comparison is made on sol–gel auto combustion methods and co-precipitation methods by preparing Nickel Zinc Ferrite (Ni0.5Zn0.5Fe2O4) nano particles. The prepared ferrite samples were calcined at different temperatures and characterized by using standard methods. X-ray diffraction analysis indicated the formation of single phase ferrite nanoparticles for samples calcined at 500°C. The lattice parameter range of 8.32–8.49Å confirmed the cubic spinel structure. Average crystallite size estimated from X-ray diffractogram was found to be between 17 and 40nm. The IR spectra showed two main absorption bands, the high frequency band ν1 around 600cm−1 and the low frequency band ν2 around 400cm−1 arising from tetrahedral (A) and octahedral (B) interstitial sites in the spinel lattice. TEM pictures showed particles in the nanometric range confirming the XRD data. The studies revealed that the sol–gel auto combustion method was superior to the co-precipitation method for producing single phase nano particles with smaller crystallite size.

Synthesis and Characterization of Nickel and Zinc Ferrite Nanocatalysts for Decomposition of CO&lt;SUB&gt;2&lt;/SUB&gt; Greenhouse Effect Gas

The decomposition of CO2 over oxygen deficient nickel ferrite nanoparticles (NFNs) and zinc ferrite nanoparticles (ZFNs) at 573 K was studied. The oxidation states with fine structure of Fe/Ni or Fe/Zn species were also measured in NFNs and ZFNs catalysts, respectively. Oxygen deficiency of catalysts was obtained by reduction in hydrogen. Decomposition of CO2 into carbon and oxygen has been carried out within few minutes when it comes into contact with oxygen deficient catalysts through incorporation of oxygen into ferrite nanoparticles. Oxygen and carbon rather than CO were produced in the decomposition process. The complete decomposition of CO2 was possible because of higher degree of oxygen deficiency andsurface-to-volume ratio of the catalysts. The pre-edge XANES spectra of Fe species in both catalysts exhibit an absorbance feature at 7114 eV for the 1s to 3d transition which is forbidden by the selection rule in case of perfect octahedral symmetry. The EXAFS data showed that the NFNs had two central Fe atoms coordinated by primarily Fe-O and Fe-Fe with bond distances of 1.871 and 3.051 angstroms, respectively. In case of ZFNs these values are 1.889 and 3.062 A, respectively. Methane gas was produced during the reactivation of NFNs by flowing hydrogen gas. Decomposition of CO2, moreover, recovery of valuable methane using heat energy of offgas produced from power generation plant or steel industry is an appealing alternative for energy recovery.

Structural, Magnetic and Dielectric Properties of Ni&lt;SUB&gt;1−&lt;I&gt;x&lt;/I&gt;&lt;/SUB&gt;Zn&lt;SUB&gt;&lt;I&gt;x&lt;/I&gt;&lt;/SUB&gt;Fe&lt;SUB&gt;2&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; (&lt;I&gt;x&lt;/I&gt; = 0,0.5 and 1) Nanoparticles Synthesized by Chemical Co-Precipitation Method

Ni(1-x)Zn(x)Fe2O4 (x = 0, 0.5 and 1) ferrite nanoparticles were synthesized by chemical co-precipitation method. X-ray diffraction technique and Rietveld refinement were used to investigate the structural characteristics and determination of the particle size which was found to decrease from 4.9 to 4.1 nm as a function of increasing Zn from 0 to 1.0. Vibrating sample magnetometer was used to study magnetic properties of nickel zinc ferrite nanoparticles. Field-dependent magnetization measurements (M-H curve) at 300 K revealed that Zn substitutions on inverse spinel nickel ferrites enhance the magnetic properties. Magnetization as a function of temperature showed the superparamagnetic behavior of Ni(1-x)Zn(x)Fe2O4 (x = 0,0.5 and 1) nanoparticles. Dielectric permittivity and a.c. conductivity were measured as a function of frequency from 100 kHz to 1 MHz at certain temperatures. The observed response in a.c. conductivity as a function of log of frequency of these nickel zinc ferrite systems was believed to be due to the presence of Maxwell-Wagner type interfacial polarization and hopping of electron by means of quantum mechanical tunneling.

Cytotoxicity of nickel zinc ferrite nanoparticles on cancer cells of epithelial origin

In this study, in vitro cytotoxicity of nickel zinc (NiZn) ferrite nanoparticles against human colon cancer HT29, breast cancer MCF7, and liver cancer HepG2 cells was examined. The morphology, homogeneity, and elemental composition of NiZn ferrite nanoparticles were investigated by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The exposure of cancer cells to NiZn ferrite nanoparticles (15.6–1,000 μg/mL; 72 hours) has resulted in a dose-dependent inhibition of cell growth determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The quantification of caspase-3 and -9 activities and DNA fragmentation to assess the cell death pathway of the treated cells showed that both were stimulated when exposed to NiZn ferrite nanoparticles. Light microscopy examination of the cells exposed to NiZn ferrite nanoparticles demonstrated significant changes in cellular morphology. The HepG2 cells were most prone to apoptosis among the three cells lines examined, as the result of treatment with NiZn nanoparticles. In conclusion, NiZn ferrite nanoparticles are suggested to have potential cytotoxicity against cancer cells.

Investigation on the Effect of NiZn Ferrite on the Mechanical and Thermal Conductivity of PLA/LNR Nanocomposites

The mechanical and conductivity of magnetic polymer nanocomposite (MPNC) of nickel zinc (NiZn) ferrite nanoparticles incorporated with poly(lactic acid) (PLA) and liquid natural rubber (LNR) as compatibilizer is reported. The matrix was prepared from PLA and LNR in the ratio of 90 : 10. The MPNC of PLA/LNR/NiZn ferrite then was prepared via Thermo Haake internal mixer using melt‐blending method from different filler loading from 1–5 wt% NiZn ferrite. The result of tensile tests showed that as the filler loading increases, the tensile strength also increases until an optimum value of filler loading was reached. Young’s modulus, tensile strength, and elongation at break have also increased. The study proves that NiZn ferrite is an excellent reinforcement filler in PLA/LNR matrix. The optimum thermal conductivity of PLA/LNR composites achieved with (4 wt% NiZn) due to the effective combination of NiZn‐NiZn conductive networks. The scanning electron micrograph (SEM) reveal that the aspect ratio and filler orientation in the PLA/LNR matrix also strongly promoted interfacial adhesion between the filler and the matrix to control its properties.

A Simple Thermal Treatment Synthesis and Characterization of Ni-Zn Ferrite (Ni0.5Zn0.5Fe2O4) Nanocrystals

Cubic structured nickel-zinc ferrite nanoparticles (Ni0.5Zn0.5Fe2O4) have been synthesized by thermal treatment method. This simple procedure employed an aqueous solution containing only metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent. The solution was thoroughly stirred for 2 hour, dried at 353 K for 3 hour, the dried material crushed into powder and calcined the powder at 873 K to remove organic substances and crystallize the particles. The microstructure properties of the prepared ferrite nanoparticles were measured using FTIR, XRD, TEM, and EDX and the magnetic properties were determined using VSM and EPR. The average particle size increased from 7 to 22 nm with the increase of calcination temperature from 723 to 873 K. The saturation magnetization, coercivity field, and g- factor increased respectively from 24 emu/g, 11 G, and 2.0673at 723 K to 38 emu/g, 60 G, and 2.1227 at 873 K. This method offers simplicity, a low cost, and an environmentally friendly operation since it produces no by- product effluents.

Synthesis and Characterization of Ni-Zn Ferrite Nanoparticles (Ni&amp;lt;sub&amp;gt;0.25&amp;lt;/sub&amp;gt;Zn&amp;lt;sub&amp;gt;0.75&amp;lt;/sub&amp;gt;Fe&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;) by Thermal Treatment Method

Cubic structured nickel-zinc ferrite nanoparticles (Ni0.25Zn0.75Fe2O4) have been synthesized by thermal treatment method. In this procedure, an aqueous solution containing metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent were thoroughly stirred, dried at 353 K for 24 h, and crushed into powder before calcination to remove organic matters and crystallize the particles. The structure and particle size were characterized by X-ray powder diffraction and transmission electron microscopy. The average particle size increased from 7 to 25 nm with increase of calcination temperature from 723 to 873 K respectively. The magnetic properties were determined by vibrating sample magnetometer and electron paramagnetic resonance electron paramagnetic resonance at room temperature. By increasing the calcinations temperatures from 723 to 873 K it showed an increase of the magnetization saturation from 11 to 26 emu/g and the g-factor from 2.0670 to 2.1220. The Fourier transform infrared spectroscopy was used to confirm the presence of metal oxide bands at all temperatures and the removal of organic matters at 873 K.

NiZn ferrite filled thermoplastic natural rubber nanocomposites: Effect of low temperature on their magnetic behaviour

The influence of temperature on the magnetic behaviour of nickel zinc ferrite nanoparticles impregnated thermoplastic natural rubber was investigated in the temperature range of 10–300K. Structural characterization was carried out using X-ray diffractometry and scanning electron microscopy. Hysteresis loops were obtained for pure and nanocomposite samples with different filler loadings at 10K and 300K using a vibrating sample magnetometer. Temperature dependence of magnetization for all samples obtained through zero-field cooling and field-cooling measurements show that the magnetization increases monotonously with decreasing temperature in case of field cooling measurement. However, the superparamagnetic behaviour through obtaining the blocking temperature was confirmed in case of zero field cooling measurement. Moreover, the width of the blocking temperature distribution was found to increase with decreasing filler content in the matrix. This result could be quite important in the biomedical applications.

Spark plasma sintering synthesis of Ni1−xZnxFe2O4 ferrites: Mössbauer and catalytic study

Nickel-zinc ferrite nanoparticles, Ni1−xZnxFe2O4 (x = 0, 0.2, 0.5, 0.8, 1.0) were prepared by combination of chemical precipitation and spark plasma sintering (SPS) techniques and conventional thermal treatment of the obtained precursors. The phase composition and structural properties of the obtained materials were investigated by X-ray diffraction and Mössbauer spectroscopy and their catalytic activity in methanol decomposition was tested. A strong effect of reaction medium leading to the transformation of ferrites to a complex mixture of different iron containing phases was detected. A tendency of formation of Fe-carbide was found for the samples synthesized by SPS, while predominantly iron-nickel alloys ware registered in TS obtained samples. The catalytic activity and selectivity in methanol decomposition to CO and methane depended on the current phase composition of the obtained ferrites, which was formed by the influence of the reaction medium.

Preparation and Structural Characterization of Vulcanized Natural Rubber Nanocomposites Containing Nickel-Zinc Ferrite Nanopowders

Single-phase polycrystalline mixed nickel-zinc ferrites belonging to Ni0.5Zn0.5Fe2O4 were prepared on a nanometric scale (mean crystallite size equal to 14.7 nm) by chemical synthesis named the modified poliol method. Ferrite nanopowder was then incorporated into a natural rubber matrix producing nanocomposites. The samples were investigated by means of infrared spectroscopy, X-ray diffraction, scanning electron microscopy and magnetic measurements. The obtained results suggest that the base concentration of nickel-zinc ferrite nanoparticles inside the polymer matrix volume greatly influences the magnetic properties of nanocomposites. A small quantity of nanoparticles, less than 10 phr, in the nanocomposite is sufficient to produce a small alteration in the semi-crystallinity of nanocomposites observed by X-ray diffraction analysis and it produces a flexible magnetic composite material with a saturation magnetization, a coercivity field and an initial magnetic permeability equal to 3.08 emu/g, 99.22 Oe and 9.42 x 10(-5) respectively.

Influence of Synthesis Temperature on Magnetic and Adsorption Properties of Nickel–Zinc Ferrite Nanoparticles by Microwave Hydrothermal Method

The microwave hydrothermal method was applied in the synthesis of Ni0.5Zn0.5Fe2 O4 ferrite nanoparticle. X-ray diffraction (XRD), infrared spectroscopy (IR) were conducted to characterize the as-prepared samples. The experiment results revealed the as-prepared nanoparticle was 8.50-10.3 nm in size with various synthesis temperatures from 40-120°C, and synthesis temperature had effects on the magnetic and adsorption properties of Ni0.5Zn0.5Fe2 O4. The saturation magnetization values increased from 22.6 to 90.8 emu g-1 with synthesis temperature increasing. Moreover, synthesis temperature also influences the adsorption capacity of methyl orange (MO) on Ni0.5Zn0.5Fe2 O4. The as-prepared Ni0.5Zn0.5Fe2 O4 showed the highest adsorption capacity of MO in the current work when synthesis temperature was 80°C, which was contributed to the more adsorption site distributed on the nanoparticle.

Structural, electrical and magnetic studies of nickel–zinc nanoferrites prepared by simplified sol–gel and co-precipitation methods

Ferrite nanoparticles, particularly nickel–zinc ferrite nanoparticles, are novel materials for high-frequency applications. Nanoparticles with a composition of Ni0.5Zn0.5Fe2O4 were prepared by two different processes, namely the co-precipitation and simplified sol-gel methods. Powder x-ray diffraction (XRD) patterns confirmed the single-phase spinel structure for the as-prepared samples. Samples were sintered at 555 and 755 °C, after which the structural, electrical and magnetic properties were studied. The crystallite sizes, as determined from XRD data, increased with sintering temperature. The dc electrical resistivity measurements were performed as a function of temperature, with the two-probe method in the temperature range from room temperature to 450 °C. The activation energy and drift mobility were calculated from the temperature-dependent dc electrical resistivity measurements. The dielectric constant and dielectric loss tangent for all the samples were determined as a function of frequency, and the frequency range used was from 20 Hz to 3 MHz at room temperature. The samples prepared using the simplified sol–gel method have lower dielectric constant values compared to those of the samples prepared using the co-precipitation method, and those prepared by the former method are more suitable for high-frequency applications. For the magnetic properties, a vibrating sample magnetometer was used. Saturation magnetization and coercivity increased with an increase in sintering temperature.

ENHANCED MAGNETIZATION IN COBALT SUBSTITUTED Ni–Zn NANOFERRITES

Cobalt substituted nickel zinc ferrite nanoparticles ( Ni 0.65–x Co x Zn 0.35 Fe 2.0 O 4) X varying from 0.0 to 0.65 in steps of 0.15 have been produced using sol–gel method, with PVA as chelating agent. The phase formation of the sintered ferrite was confirmed by X-ray diffraction studies. The lattice parameter a(A°) has been calculated using Nelson–Riley method. The crystallite size has been estimated by the Williamson–Hall method using the full width at half-maximum (FWHM) of the line broadening of all the peaks. Mössbauer spectroscopy (MS) of the samples showed the clear presence of two sextets and distribution of iron over the two sites has been given. Increase in saturation magnetization with cobalt concentration with a slight decrease for x = 0.15 has been observed with the vibrating sample magnetometry study. The observed value of magnetization for Ni0.65Zn0.35Fe2O4 with a particle size of 43.5 nm has been 71 emu/gm at room temperature, which is higher than that reported for samples prepared using chemical methods of the same composition. The results have been explained on the basis of the particle size and cation distribution among various sites.

Characterization of nanodimensional Ni-Zn ferrite prepared by mechanochemical and thermal methods

Nickel zinc ferrite nanoparticles, Ni1−xZnxFe2O4 (x = 0, 0.2, 0.5, 0.8, 1.0), with dimensions below 10 nm have been prepared by combining chemical precipitation with high-energy ball milling. For comparison, their analogues obtained by thermal synthesis have also been studied. Mössbauer spectroscopy, X-ray diffraction, and magnetic measurements are used for the characterization of the obtained materials. X-ray diffraction shows that after 3h of mechanical treatment ferrites containing zinc are formed, while 6h of treatment is needed to obtain NiFe2O4. The magnetic properties of the samples exhibit a strong dependence on the phase composition, particle size and preparation method.

Annealing temperature and initial iron valence ratio effects on the structural characteristics of nanoscale nickel zinc ferrite

Nickel zinc ferrite (NZFO) nanoparticles were synthesized via a reverse micelle method with a nonionic surfactant. Three different initial Fe3+/Fe2+ ratios were employed along with three different firing temperatures (200, 500, 1000 °C) to investigate the effects on the NZFO system. Extended x-ray absorption fine structure (EXAFS) results reveal zinc loss at high annealing temperatures; at 1000 °C, the loss is nearly total for Fe3+/Fe2+ ratios other than 10:90. Annealing at 500 °C, however, appears necessary for fully incorporating the zinc and nickel into the spinel phase. The best nanoferrite was thus obtained using an initial Fe3+/Fe2+ ratio of 10:90 and a moderate firing temperature of 500 °C. This sample exhibits a room temperature saturation magnetization of 58 emu/g as measured via vibrating sample magnetometry, comparable with bulk values and greater than that of confirmed nano-NZFOs found in the literature. EXAFS also indicates that in all cases in which the elements adopted a spinel structure, the nickel occupies only octahedral sites and the zinc primarily tetrahedral sites.