Self-combustion Technique Research Articles

Analysis of the Structural, Morphological, and Elastic Properties of Nanosized CuFe2O4 Spinel Synthesized via Sol-Gel Self-Combustion Method

Nanosized CuFe2O4 ferrite was synthesized through the sol-gel self-combustion technique, using iron and copper nitrates with citric acid as fuel. The synthesized ferrite was subsequently analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). X-ray diffraction studies validated the crystalline nature of the CuFe2O4, identifying it as having a mixed spinel structure within the Fd3m space group. Particle sizes were quantified using several methods including Debye-Scherrer, Williamson-Hall, Halder-Wagner, modified Debye-Scherrer, and size-strain plot (SSP), with all methods indicating a consistent average particle size of 28 nm. The elastic properties of the nanoparticles were extensively characterized, utilizing both diffraction line broadening (via the Williamson-Hall method) and Fourier-transform infrared spectroscopy (FTIR) to evaluate the materials' structural dynamics. Additionally, microstrain within the crystal lattice and various elastic constants, such as Young's modulus, Shear modulus, Debye temperature, and the velocities of longitudinal and transverse wave propagation were calculated. An electron density distribution was also constructed from the X-ray diffraction data, providing insight into the electronic environment and bonding characteristics of the material.

La3+ ion doped Cd0.5C0.5LaxFe2-xO4 nanomagnetic materials for high-frequency device applications

The sol-gel self-combustion technique was applied to form Cd–Co-based La-doped (Cd0.5Co0.5LaxFe2-xO4) spinel ferrite nanoparticles. A series of six samples was synthesized by varying lanthanum content from x = 0.00 to 0.20. The structural characteristics of the prepared nanoparticles were carried out using X-ray diffraction (XRD) analysis. The (311) plane verified that the prepared nanomaterials are in the spinel phase in all observed XRD patterns. The crystallite size for each sample was determined using the Scherrer formula found in the 8.7–17.8 nm range, which is well correlated with the SSP model. The crystallite size decreased while the lattice constant increased from 8.38 to 8.45 Å with increasing La-content. The increasing trend in the bulk density and X-ray density has been analyzed with the effects of La3+ contents. In Fourier-transform infrared spectroscopy (FTIR), the high-frequency absorption band (υ1) was found from 522.15 to 541.06 cm−1, whereas the low-frequency band (υ2) varied from 419.80 to 414.31 cm−1. The surface morphology was carried out by scanning electron microscope (SEM), which positively correlated with XRD analysis. Impedance analyzer (IA) assisted in observing the variations in complex dielectric properties of the compound in the frequency range from 1 MHz to 3 GHz. The dielectric constant and impedance plots depicted that the nano ferrites have good dielectric properties in low-frequency regions due contribution of polarization. While conduction can be made possible in the high-frequency areas as observed through AC conductivity. The electric modulus revealed the relaxation phenomenon at high frequency due to the hopping of electrons at the octa and tetrahedral sites. The magnetic properties were investigated to study the impact of La3+ ion under the applied magnetic field from −15 to 15 kOe. The saturation magnetization, and magnetic remanence were found from 40.6 to 27.7 emu/g and 19.6 to 2.7 emu/g, respectively. The synthesized nanoparticles can be utilized for microwave applications and magnetic storage devices.

Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

Abstract: Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

Preparation and characterisations of magnetic nanofluid of zinc ferrite for hyperthermia

Zinc ferrite (ZnFe2O4) nanoparticles were synthesised by using solution gelation and the self-combustion technique. The resulting zinc ferrite nanoparticles were structurally analysed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometry for structural, morphological and magnetic properties, respectively. The XRD pattern shows that the prepared sample has a spinel monophasic cubic structure, and the broadening of X-ray peaks indicates the nanocrystalline size of the particles to be on the order of 13 nm. FE-SEM analysis shows spherical-type grains and confirms the nanocrystalline nature with an average grain size of 24 nm. The energy-dispersive X-ray analysis spectrum indicates the purity of the sample and the presence of the desired ions in good proportions. The magnetisation–field strength (M–H) hysteresis loop shows enhanced magnetisation with the superparamagnetic nature of zinc ferrite nanoparticles compared with previous literature reports. The saturation magnetisation value (M s) was estimated to be 23·25 emu/g. The obtained nanoparticles of zinc ferrite were used to prepare nanofluids with water as a base fluid (2 mg/ml concentration). Magnetic hyperthermia studies were carried out using an induction heating system. The induction heating results show that a small amount (2 mg/ml) of zinc ferrite nanoparticles can achieve a 42°C temperature for 258 s at 4·0 kA/m.

Structure and cation distribution in superparamagnetic NiCrFeO4 nanoparticles using Mössbauer study

The structure and cation distribution in nanoparticles of chromium doped nickel-ferrite synthesized using the solution self-combustion technique has been studied using Mössbauer spectroscopy. Powder XRD analysis of samples confirmed the formation of single-phase pure NiCrFeO4 nanoparticles. The structural parameters were investigated by powder X-ray diffraction followed by Rietveld refinement using the FullProf method. The crystallite size obtained from XRD matches well with the particle size seen in TEM. From the room-temperature Mössbauer study, NiCrFeO4 nanoparticles are found to exhibit superparamagnetism. The low-temperature Mössbauer studies indicate superexchange interaction between A and B sites, novel cation distribution, (Fe0.2Ni0.8)A [CrNi0.2Fe0.8]B with an unusual presence of Ni2+ at A site and spin canting effects.

Crystallization, non-isothermal kinetics and structural analysis of nanocrystalline multiferroic bismuth ferrite (BiFeO3) synthesized by combustion method

The synthesis of bismuth ferrite (BiFeO3) in the nanocrystalline form is described in the present work with the help of self-combustion technique with DL-malic acid as fuel to obtain single-phase BiFeO3 nanopowders. The crystallization behavior for the formation of BiFeO3 was confirmed from the obtained powder diffraction pattern (p-XRD) and thermogravimetric analysis with simultaneous differential thermal analysis. Thermal measurements were carried out in the nitrogen atmosphere to determine the crystallization kinetics through various heating rates from simultaneous thermogravimetric–differential thermal (TG–DTA) analysis curve. The activation energies for the formation of BiFeO3 metal oxides formation were found to be around 124 kJ mol−1 and 113 kJ mol−1 from the phenomenological Johnson–Mehl–Avrami equation or in short JMA. The growth mechanism along three dimensions was observed for all heating rates. The formation of single-phase BFO in nanocrystalline nature was confirmed through microstructural investigations by the use of transmission electron microscopic analysis. The selected area electron diffraction pattern of nanostructure bismuth ferrite for the sample calcinated at 800 °C reveals the diffraction miller indices planes {104} and doublet peaks of {110}, {202} which is in good agreement with that of the present powder XRD pattern. The magnetization for the synthesized samples calcinated indicates that there exists the magnetic order and existence of room-temperature magnetic saturation for the multiferroic BiFeO3.

Adsorption of asphaltenes on mixed oxide synthesized by auto-combustion method

The oil classified as heavy is the one with the largest number of deposits at present. However, these deposits are usually difficult to exploit since they contain a high concentration of asphaltenes which cause problems in the refineries at the time of extraction. Different strategies were used to decrease the effects of asphaltenes, being the most effective the use of adsorbents based on metal oxides. This is because metal oxides prevent the re-precipitation of asphaltenes under oil extraction; these methods can be easy implemented in modern refineries.In this work, we propose the synthesis of mixed oxide (Ni(3/2)xFe2-xO4) by self-combustion technique, being then used as an effective asphaltene adsorbent. Its asphaltene adsorption capacity was compared with nickel oxide and hematite, which were synthesized by controlled precipitation. The oxides were characterized by the techniques of X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR); their morphological characterization was carried out by scanning electron microscopy (SEM). The capacity of adsorption of asphaltenes was determined with the technique of UV-Vis spectroscopy. The results show that the Ni(3/2)xFe2-xO4 is a good adsorbent being compared with hematite and nickel oxide, both for asphaltenes with ether and amino groups. The mixed oxide shows a mayor affinity to asphaltenes containing amino groups, being compared with the hematite and nickel oxide; in addition, the mixed oxide has a low affinity to petroleum, which makes it selective to asphaltenes.

Comparative study of microwave absorption characteristics of (Polyaniline/NiZn ferrite) nanocomposites with different ferrite percentages

We present the preparation of polyaniline/Ni0.5 Zn0.5Fe2O4 (PANI/NiZn ferrite) nanocomposite. The preparation process consists of two steps: First, the ferrite is synthesized by self-combustion technique using sucrose as fuel. Then, the process is continued by in-situ chemical oxidative polymerization of aniline in the presence of the ferrite. Three different weight ratios of PANI/NiZn ferrite (1:2, 1:1, and 2:1) are prepared and structurally characterized by SEM, XRD, FT-IR and UV-vis spectroscopy. The functional characterization is performed by measuring the dc-conductivity, and microwave absorption characteristics in the range (8–12 GHz). XRD patterns prove the formation of the spinel ferrite, while SEM analysis indicates that the change in PANI/NiZn ferrite ratio has an effect on the morphology, which eventually influences the microwave absorption characteristics of the composite. A maximum reflection loss of −39.56 dB at 11.0 GHz with a matching thickness of 2.5 mm and a bandwidth of 3.0 GHz is obtained for PANI/NiZn ferrite having a weight ratio of 1:1 with only 25%w/w load in paraffin.

Low-temperature magnetic properties of NiCrxFe2–xO4 ferrites

Nickel-chrome ferrites of general formula NiCrxFe2–xO4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) were produced using low-temperature sol-gel self-combustion technique. Magnetic hysteresis loop of the samples showed that due to a low coercive field Hc, in the range of 2484–4283 A/m at 77 K, the ferrites are soft magnetic materials. The residual induction Br of the magnetic field decreases with increasing the concentration of Cr3+ ions due to a weakening of the interaction between the tetrahedral and octahedral sublattices of the ferrite with the spinel structure. The specific saturation magnetization σs of NiFe2O4 ferrite is 33.9 A m2/kg. The blocking temperature Tb was determined; its average value was found to be 157 K.

Zinc Oxide Nanoparticles: chemical, physical and Biosynthesis Synthesis and its some Applications

This review article described the major synthesis of Zinc oxide nanoparticles with various ways, such as physical synthesis, chemical synthesis and Biosynthesis. Chemical synthesis as Hydrothermal Technique, Vapor Transport, Precipitation Method, Self-Combustion technique, Sol-gel method and microemulsion method. Physical synthesis as high-energy ball milling method, laser ablation method and Physical vapor deposition method. Biosynthesis Includes synthesis through fungi, plants, bacteria Some applications of zinc oxide nanoparticles have been listed.

Investigation on impedance response and dielectric relaxation of Ni-Zn ferrites prepared by self-combustion technique

Abstract Nanocrystalline mixed Ni1-xZnx Fe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1) have been achieved by low temperature self-combustion technique using oxylyldehydrazide (ODH) as fuel. The structural, morphological and dielectric properties were studied using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman Spectroscopy and frequency dependant impedance spectroscopy with frequency range from 1 Hz to 107 Hz. The XRD analyses of as prepared samples show single phase cubic spinel structure with Fd-3m space group. The average crystallite size was estimated using Debye-Scherer's formula and was found to be in the range 15–30 nm. FTIR spectra shows two prominent absorption bands, the higher band at tetrahedral (A) sites and the lower band at octahedral (B) site. The Raman peaks above 600 cm−1 correspond to A1g type, involving motions of O atoms in the tetrahedral group (A-site) and the other low frequency peak 241, 335 and 480 represent the characteristics of the octahedral group (B-site) of ferrites. SEM images shows that all the samples have nano crystalline behavior with spherical shape. EDX confirms the constitutional distribution of prepared samples. The dielectric properties such as dielectric constant e′, dielectric loss tangent and ac conductivity were found to be lowest for x = 0.8. The grain and grain boundary contributions in nano ferrites have been explained using Nyquist plot. The prepared mixed ferrites are good material for frequency dependent applications.

Electrical conductivity and magnetic field dependent current-voltage characteristics of nanocrystalline nickel ferrite

We have studied the grain size dependent electrical conductivity, dielectric relaxation and magnetic field dependent current voltage (I−V) characteristics of nickel ferrite (NiFe2O4). The material has been synthesized by sol-gel self-combustion technique, followed by ball milling at room temperature in air environment to control the grain size. The material has been characterized using X-ray diffraction (refined with MAUD software analysis) and Transmission electron microscopy. Impedance spectroscopy and I−V characteristics in the presence of variable magnetic fields have confirmed the increase of resistivity for the fine powdered samples (grain size 5.17±0.6nm), resulted from ball milling of the chemical routed sample. Activation energy of the material for electrical charge hopping process has increased with the decrease of grain size by mechanical milling of chemical routed sample. The I−V curves showed many highly non-linear and irreversible electrical features, e.g., I−V loop and bi-stable electronic states (low resistance state-LRS and high resistance state-HRS) on cycling the electrical bias voltage direction during I-V curve measurement. The electrical dc resistance for the chemically routed (without milled) sample in HRS (∼3.4876×104Ω) at 20V in presence of magnetic field 10kOe has enhanced to ∼3.4152×105Ω for the 10h milled sample. The samples exhibited an unusual negative differential resistance (NDR) effect that gradually decreased on decreasing the grain size of the material. The magneto-resistance of the samples at room temperature has been found substantially large (∼25–65%). The control of electrical charge transport properties under magnetic field, as observed in the present ferrimagnetic material, indicate the magneto-electric coupling in the materials and the results could be useful in spintronics applications.

Synthesis and characterization of some nanostructured composite oxides for low temperature catalytic combustion of dilute propane

Five nanosized perovskite and four ferrospinel powders were prepared by sol–gel self-combustion technique. The La0.6Pb0.2Mg0.2MnO3 perovskite was found to exhibit the best catalytic performance with respect to propane combustion at low temperatures.

Synthesis and characterization of NiO-ZnO nanocomposite by a cost efficient self-combustion technique

Purpose: In this research work the nickel oxide incorporated zinc oxide nano compositewith various level of percentage such as (0.2, 0.4 and 0.6) were synthesized usingcombustion processes. Fuel used for the combustion process is hexamine in this work.Oxidizing agents taken were the nitrates of zinc and nickel. These precursor nitrates wereheated with hexamine fuel to undergo combustion process.Design/methodology/approach: After combustion the particles were collected and heattreated to maintain the purity of the samples. XRD results were in well accordance withthe JCPDS data and the average crystalline sizes were in the range of 10~20 nm. UV-VISabsorbance results confirm the band gap in the visible region. With increase in concentrationof NiO in the composite red shifted from 320 nm to 374 nm. FTIR supports the presenceof Zn-O and Ni-O bonds by the characteristic vibrational peaks at 432 cm-1 and 470 cm-1respectively. PL spectrum studies results in the redshift of ZnO peaks from 380 nm to 400 nmwith addition of Ni2+ ions inside the lattice. SEM and AFM studies reveals the morphologicaland topographical visualizations of the nanocomposite powders.Findings: In this research work, the authors had successfully synthesized Nickelsubstituted Zinc oxide by following simple combustion method followed by annealing. XRDanalysis clearly evidences the formation of ZnO in the hexagonal wurtzite structure with anaverage crystallite size of 15 nm to 18 nm. An increase in Nickel peaks in between the Zincoxide peaks were observed with increase in the nickel concentration in the composition.Practical implications: We conclude that combustion technique is suitable to fabricateNickel incorporated Zinc oxide particles with high purity. This powder can be used intransparent conducting thin flims for OLED applications.

Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4) and Zinc Ferrite (ZnFe2O4) Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

Spinel copper ferrite (CuFe2O4) and zinc ferrite (ZnFe2O4) nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg) and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL) of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

Influence of particle size on H2 and H2S sensing characteristics of nanocrystalline zinc ferrite

Nanocrystalline zinc ferrite ZnFe2O4 was synthesized by sol–gel self-combustion technique. Ball milling at room temperature was carried out to control the particle size. Characterization of synthesized powders was made using X-ray diffraction and transmission electron microscopy analysis. Fine powders resulted from milling were used to prepare gas sensing elements in pellet form. The gas-sensing properties were studied in presence of hydrogen and hydrogen sulphide as test gases. The gas response behavior was found to be strongly influenced by the particle size. Significantly high sensitivity of ~82 % was found for ~7 nm zinc ferrite in presence of 200 ppm H2S at an operating temperature of 150 °C. Sensitivity was found to increase with temperature before being maximum at a particular operating temperature.

Synthesis, Characterization and in Vitro Evaluation of Manganese Ferrite (MnFe2O4) Nanoparticles for Their Biocompatibility with Murine Breast Cancer Cells (4T1).

Manganese ferrite (MnFe2O4) magnetic nanoparticles were successfully prepared by a sol-gel self-combustion technique using iron nitrate and manganese nitrate, followed by calcination at 150 °C for 24 h. Calcined sample was systematically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and vibrational sample magnetometry (VSM) in order to identify the crystalline phase, functional group, morphology, particle size, shape and magnetic behavior. It was observed that the resultant spinal ferrites obtained at low temperature exhibit single phase, nanoparticle size and good magnetic behavior. The study results have revealed the existence of a potent dose dependent cytotoxic effect of MnFe2O4 nanoparticles against 4T1 cell lines at varying concentrations with IC50 values of 210, 198 and 171 μg/mL after 24 h, 48 h and 72 h of incubation, respectively. Cells exposed to higher concentrations of nanoparticles showed a progressive increase of apoptotic and necrotic activity. Below 125 μg/mL concentration the nanoparticles were biocompatible with 4T1 cells.

Self-Combustion Synthesis of Co–Zr-doped Ba-Hexaferrite Nanoparticles and Their Studied Physicochemical and Magnetic Properties

In our efforts to investigate the correlation between distributions of cations over five crystallographic positions, magnetic properties of Ba-hexaferrites (BaM) in the coupled substitution of magnetic Co2+ and nonmagnetic Zr4+ for Fe3+ were examined. During the present research, we have synthesized a series of BaCo x Zr x Fe(12−2x)O19 (x = 0.0−1.0) ferrites by self-combustion technique using urea as a fuel at a temperature of 950 ∘C. M-type hexagonal ferrites with some α–Fe2O3 phase have been confirmed by powder X-ray diffraction, and the average size of hexagonal platelets was 64 nm which was comparable with transmission electron microscopy (TEM). Metal oxide peaks in the region of 600–400 cm−1 in Fourier transform infrared spectroscopy (FT-IR) spectra confirm the structure coincidence with X-ray diffraction (XRD) results. The Brunauer–Emmett–Teller (BET) surface area (9.72 m2/g) and mesopore diameter (22.55 nm) of samples have been observed by using the Barrett–Joyner–Halenda (BJH) method. Mossbauer studies suggest that dopant ions largely preferred 4 f 2 sites up to x = 0.6 while substitution at 4 f 1 and 12k sites were indicated at higher concentrations. Magnetization measurements showed that the coercive force was steeply reduced from 4348 to 696 Oe with increasing Co–Zr contents but net magnetization was nearly constant (M S = 52.34−57.47 emu/g). High M S and low H C values of our materials make them particularly suitable for many electrical devices.

Influence of particle size on H2 and H2S sensing characteristics of nanocrystalline nickel ferrite

Nanocrystalline nickel ferrite (NiFe2O4) was synthesized by sol–gel self-combustion technique. Ball milling at room temperature was carried out to control the particle size. Characterization of synthesized powders was made using X-ray diffraction (XRD) and Transmission electron microscopy (TEM) analysis. Fine powder resulted from milling was used to prepare gas sensing elements in pellet form. The gas-sensing properties were studied in presence of hydrogen and hydrogen sulfide as test gases. The gas-response was found to be strongly influenced by the particle size. Significantly high sensitivity of ~75% was found for ~5.35nm nickel ferrite in presence of 200ppm H2S at an operating temperature of 150°C. Sensitivity was found to increase with temperature before being maximum at a particular operating temperature.

Synthesis and Characterization of Zinc Oxide Nanoparticles via Self-Combustion Technique

Zinc oxide (ZnO) is a unique material which has been used in many researches. However synthesizing nanosize ZnO remains a challenge. This deal with the preparation of ZnO nanoparticles was synthesized by a self-combustion technique. In the self-combustion technique, nanoparticles was obtained by heating the materials until the mixture combusts at 110°C. ZnO nanoparticles were synthesized from Zn (NO3)2.6H2O precursor observed in two different solvent. The first set of experiment involved dissolving Zn (NO3)2.6H2O in nitric acid (HNO3) and adding ZnO, whereas for the second Ethylene Glycol (C2H6O2) was used as the solvent. The material was stirred at 250 r.p.m continuously for 1 month and 3 days. The mixture was then heated up until it combusted at 110°C. Samples were then annealed at 400°C for 1 hour . The ZnO samples were characterized using X-Ray Diffraction (XRD), Raman Spectroscopy, and Field Emission Scanning Electron Microscope (FESEM). The XRD analysis showed major peak at 20-30 of 2 theta scale with [10, [00, and [10 plane of the wurtzite hexagonal structure for both sets of ZnO samples. Samples were observed at raman shift for 138 and 439 cm-1 and 141 and 443 cm-1 before and after annealing. Synthesized ZnO 1 resulted the morphology of single crystal nanorods with average dimensions of 18 nm wide and 154 nm long. ZnO 2 has obtained the morphology of single crystal nanosphere with average diameter of 30 nm.Keywords: Zinc Oxide, Ethylene Glycol, Self-Combustion Technique