Synthesis Of Nickel Ferrite Research Articles

Nickel ferrite: synthesis and application for voltammetric determination of uric acid

In this paper, the synthesis of nickel ferrite and its use for voltammetric determination of uric acid (UA) are presented. Nickel ferrite was synthesized via a hydrothermal process using spherical carbons as hard template followed by calcination at 500 °C. It was found that iron and nickel compositions in nickel ferrite can be controlled by the initial Fe/Ni molar ratio. The stoichiometric nickel ferrite (NiFe2O4) with hollow spherical morphology was obtained from a reaction mixture with Fe/Ni molar ratio of around 1.2–1.5. Glassy carbon electrode modified with nickel ferrite was employed to quantitatively determine UA by different pulse voltammetric method. Under the optimum conditions, the anodic peak current was linearly proportional to UA concentration in the range of 0.398 to 6.761 μM. The detection limit (3σ) was found to be 0.15 μM. The proposed method has been employed to determine UA in human urine samples with acceptable recoveries of 95.15–104.8%. On the other hand, the results obtained from this method were also compared with that from standard HPLC method, showing no statistical difference.

Magnetic Properties of Nickel Ferrite Magnetic Nanoparticles Prepared via Glycine Assisted Sol-Gel Auto Combustion Route

The present research paper deals on the synthesis of nickel ferrite (NiFe2O4) nanoparticles using sol-gel auto combustion technique in which glycine was used a chelating agent. The prepared nanoparticles were annealed at 500°C for 4 h. and then used for structural, magnetic and other investigations. The X-ray diffraction technique was used for phase purity and structural determination. Room temperature X-ray diffraction pattern of NiFe2O4 nanoparticles shows all the reflections belonging to cubic spinel structure. The reflections are intense and slightly broader. No extra peak other than cubic spinel structure was observed in the XRD pattern. This indicates the single phase formations of the nickel ferrite nanoparticle. The refinement of XRD data has been carried out by using full proof programmer. The lattice constant was calculated using XRD data as well as Cohen’s least square method, the obtained lattice constant matches with the reported value. The other structural parameters like lattice strain, X-ray density etc. structural parameters were also calculated using standard relations. The crystallite size was determined using Scherrer’s formula in which the most intense peak (311) was considered. The crystallite size was found to be 24 nm which indicates the nanocrystalline nature of the prepared nickel ferrite nanoparticles. The magnetic properties of were investigated using the pulse field hysteresis loop (PFHL) technique at room temperature. The saturation magnetization, coercivity and remanence magnetization shows enhanced values. All the structural and magnetic properties results were compared with the reported data in which other chelating agent like citric acid etc.

APROVECHAMIENTO DE RESIDUO DE BIOMASA FÚNGICA EN LA OBTENCIÓN DE UN SISTEMA MAGNÉTICO NANOESTRUCTURADO PARA REMOVER ARSÉNICO DEL AGUA

Application of filamentous fungi in biotechnological processes leads to the accumulation of biomass as waste. However, it is known that the fungal biomass contains various biopolymers among which is chitin -the precursor of chitosan. In the present work, fungal biomass was used as raw material for the extraction of a biopolymer containing chitosan by the acid/alkaline method. Different extraction conditions were assayed: the concentration of alkali, time, and temperature of treatments. The biopolymer was characterized and applied in the synthesis of nickel ferrite by the coprecipitation method demonstrating the possibility of obtaining a nanostructured magnetic system coated with fungal chitosan in a single step. The properties of the obtained nanostructured magnetic material were evaluated by X-ray diffraction, vibrating sample magnetometry, and Fourier-transform infrared spectroscopy. It was demonstrated that the nanostructured magnetic material coated with fungal chitosan removes 100 % of the arsenic present in a sample from a well of Comarca Lagunera (states of Durango and Coahuila, Mexico), as well as other ions that are not harmful to health. It was found that the capacity to remove arsenic is conserved in at least 15 tests of magnetic separation of this toxic pollutant. The results of the present work demonstrate the possibility of taking advantage of the fungal biomass residue, currently little used, for the design of magnetic nanomaterials with impact on the elimination of water from toxic pollutants by magnetic separation.

Synthesis, Characterization, and Sensing Performance Investigation of Nickel Ferrite Nanoparticles for Ammonia Detection

In this article, NiFe2O4 nanocrystals were prepared through the co-precipitation method. The two variables in the nickel ferrite synthesis were the temperature gradient of reaching the heat treatment temperature and the pure oxygen pressure of the heat treatment atmosphere. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray fluorescence (XRF) spectroscopy experiments were used to verify the formation of the ferrite phases, the formation of the ferrite nanostructure phase, the proper morphology of the particles, and the accuracy of the atomic ratios of the ferrite product, respectively. NiFe2O4 nanocrystals as ammonia gas sensors were evaluated at 65 °C. A laboratory device with the capability of temperature and humidity control and with the capacity of 5 L was used to test the susceptibility of nanosensors. This device was equipped with a temperature control heater, and then sensors were placed on this device. A gas injection chamber and an electronic interface board were also used. After that, nanosensors’ data were transmitted to a computer system and were analyzed by LabVIEW software. In our study, we found that both the variables in the nickel ferrite synthesis have a role in resistivity variations in sensors. The effect of the atmospheric oxygen pressure on the heat treatment was approximately equal to the temperature gradient reaching the temperature of the heat treatment. In addition, the synthesized sensor with a 10 °C/s temperature gradient and an oxygen atmosphere of 1.5 psi was better than the other eight nanosensors. This sensor is determined as the superior nanosensor, and the relationship between gas concentration and resistivity in this nanosensor is reported.

X-Ray and Thermogravimetric Analyzes of Mechanically Activated Nickel Ferrites

This article shows a study of the effect of mechanical activation of the initial mixture of reagents NiO and Fe2O3 at different speeds of grinding bowl rotation on synthesis of nickel ferrite. Nickel ferrite was produced by the solid-phase synthesis at a temperature of 900 °C for 240 minutes. The obtained ferrite samples were investigated by thermal gravimetric and X-ray phase analysis. The Curie temperature values are obtained, as well as the magnitude of the change of detected instrument weight at the magnetic phase transition (ferromagnetic-paramagnetic) of nickel ferrite using thermal gravimetric curves (TG/DTG) with applied external magnetic field. Increasing of the homogeneity degree of ferrite materials with an increase in the mechanical activation rate is shown based on the data of X-ray phase analysis. The experimental results obtained from thermal, magnetic, and X-ray analyzes were compared.

An approach to nickel ferrite synthesis

In this letter, a new approach to the synthesis of nickel ferrite has been performed. Nickel ferrite nanoparticles have been prepared via a straightforward method by simply heating iron-nickel tertracyanide powder (FeNi(CN)4·3H2O) in air at 400 °C for only 5 min. During the heating process, it was observed that iron-nickel cyanide powder ignites at a certain point in the material and then this ignition propagates in a wave-like manner through the rest of the mass. As the ignition front propagated through the material, an extreme expansion occurred in a way similar to musical accordion and eventually formed nickel ferrite nanoparticles. Samples were characterized using XRD, SEM, HRTEM, TGA and Raman spectroscopy. All analysis confirmed the successful formation of single phase nickel ferrite. The present method can be extended to synthesize other ferrites. The presented approach is characterized by both simplicity and scalability which makes it promising for industrial utilization.

Multiferroic Core-Shell Nanofibers, Assembly in a Magnetic Field, and Studies on Magneto-Electric Interactions.

Ferromagnetic–ferroelectric nanocomposites are of interest for realizing strong strain-mediated coupling between electric and magnetic subsystems due to a high surface area-to-volume ratio. This report is on the synthesis of nickel ferrite (NFO)–barium titanate (BTO) core–shell nanofibers, magnetic field assisted assembly into superstructures, and studies on magneto-electric (ME) interactions. Electrospinning techniques were used to prepare coaxial fibers of 0.5–1.5 micron in diameter. The core–shell structure of annealed fibers was confirmed by electron microscopy and scanning probe microscopy. The fibers were assembled into discs and films in a uniform magnetic field or in a field gradient. Studies on ME coupling in the assembled films and discs were done by magnetic field (H)-induced polarization, magneto–dielectric effects at low frequencies and at 16–24 GHz, and low-frequency ME voltage coefficients (MEVC). We measured ~2–7% change in remnant polarization and in the permittivity for H = 7 kOe, and a MEVC of 0.4 mV/cm Oe at 30 Hz. A model has been developed for low-frequency ME effects in an assembly of fibers and takes into account dipole–dipole interactions between the fibers and fiber discontinuity. Theoretical estimates for the low-frequency MEVC have been compared with the data. These results indicate strong ME coupling in superstructures of the core–shell fibers.

Size-controlled synthesis of NiFe2O4 nanospheres via a PEG assisted hydrothermal route and their catalytic properties in oxidation of alcohols by periodic acid

A novel and facile approach for synthesis of spinel nickel ferrites (NiFe2O4) nanoparticles (NPs) employing homogeneous chemical precipitation followed by hydrothermal heating is reported. The synthesis involves use of tributylamine (TBA) as a hydroxylating agent in synthesis of nickel ferrites. Polyethylene glycol (PEG) 4000 was used as surfactant. As-synthesized NiFe2O4 NPs were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption isotherm (BET) and vibrating sample magnetometry (VSM). The XRD pattern revealed formation of cubic face-centered NiFe2O4 and TEM image showed spherical particles of sizes 2–10nm. These NiFe2O4 NPs were used as magnetically recoverable catalyst in oxidation of cyclic alcohols to their corresponding aldehydes by periodic acid. This eco-friendly procedure affords products in very high yield and selectivity. The reusability of the catalyst is proved to be noteworthy as the material exhibits no significant changes in its catalytic activity even after five cycles of reuse.

The effects of heat treatment on the synthesis of nickel ferrite (NiFe2O4) nanoparticles using the microwave assisted combustion method

NiFe2O4 nanoparticles were synthesized using the microwave assisted combustion method based on metal nitrate salts and urea. To remain of organic matters and to stabilize the particles, samples were thermally treated at various temperatures from 300–800 °C. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The heat treated samples show the reflection planes of (111), (220), (222), (311), (400), (422), (511), and (440) which perfectly confirm to a cubic spinel phase of NiFe2O4 and no secondary phases were detected in the XRD patterns of the samples. The crystallite sizes calculated using the Debye–Scherrer formula were found to increase with the heat treatment temperature, from about 4 nm at 300 °C–85 nm at 800 °C. EDX results verify that the compositional mass rations were relevant, as expected from the synthesis. The micrographs of SEM and TEM showed that all of the samples have nano-crystalline behavior and particles indication cubic shape. Magnetization measurements were obtained at room temperature by using a VSM, which demonstrated that the all of the samples synthesized with heat treatment exhibited ferromagnetic behaviors.

Influence of the starting powders on the synthesis of nickel ferrite

AbstractThe thermal decomposition of freeze‐dried nickel(II)‐iron(III) formate was investigated by means of DTA, TG, mass spectrometry and X‐ray powder diffractometry. For the preparation of homogeneous freeze‐dried nickel(II)‐iron(III) formate precursors, a rigorous control of nickel ion concentration in the precursor solution was required. The decomposition of the reactive nickel(II)‐iron(III) formate does not only reflect aspects of single formates, but also an interaction between components which lowers the decomposition temperature. Crystalline nickel ferrite powders were obtained at 600‐800°C. This temperature is quite lower than 1100°C employed for the ceramic method. In the presence of air, the regeneration of nickel ferrite from the taenite phase (γNi,Fe) is accomplished at 800°C. This temperature is also 300°C below the temperature employed when the mixtures NiO:α‐Fe2O3 or Ni:2Fe are the starting powders. The main reason for the high reactivity of the freeze‐dried formates and the taenite alloy is the large homogeneity of these precursors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Thin films of ferrite and ferroelectric materials deposited by pulsed laser vaporization process

Abstract Thin films of BaTiO3 and Ni x Fe3−x O4 have been obtained by pulsed ruby laser evaporation process. In the case of BaTiO3 a sintered bulk pellet was used as the vaporization source, while Fe50Ni50 metallic alloy was used as the source for synthesis of nickel ferrite. The dependence of the film properties on oxygen partial pressure and laser energy density during deposition has been investigated. It is shown that thin films of these materials having good structural, morphological and stoichiometric properties can be obtained by the laser process by appropriate control of process parameters.

Synthesis of nickel ferrite from polynuclear coordination compounds

Synthesis of nickel ferrite from polynuclear coordination compounds