Citrate-gel Auto Combustion Method Research Articles

Eu3+ Doped CoFe2O4 Nanoparticles with XRD and FTIR Analysis

Pure and Eu3+ doped cobalt ferrite nanoparticles with the formula CoEuxFe2-xO4(x = 0.00,0.10) were synthesized by citrate gel auto combustion method. X-ray diffraction analysis validated both the phase formation and purity of the synthesized nanoparticles. The Fourier-transform infrared (FTIR) spectra of the sample were meticulously recorded within the spectral range of 200-1000 cm^-1. This analysis provided insights into the formation of the spinel structure.

Structural and Electrical Properties of Li Substituted Mg Nano Ferrites: Prepared by Citrate-gel Auto Combustion Method

LixMg1−xFe2O4 where x=0.0to0.5with0.1 nano ferrites were synthesized by citrate gel auto combustion. Using a field-emission scanning electron microscope (FE-SEM) and the X-ray diffraction technique, their structural and topographical studies were examined. The prepared nano ferrites’ single-phase cubic spinel along the Fd3m space group is confirmed by the structural investigation. The synthesized samples were found to have a crystalline size of 20–26 nm, as determined by the Debye–Scherrer formula. Lattice parameter variation observed for the samples indicates dopant atoms into a crystal lattice can also lead to changes in the lattice constant. FE-SEM images revealed the clear grain and grain boundaries with agglomerated structure and it varied between 33.6 nm-24.4 nm. Two bands observed in Fourier transform infrared spectroscopy illustrates the M-O band in tetrahedral and octahedral sites. Dielectric parameters of the sample observed by LCR meter. Single semicircle behavior observed in impedance spectra. Dielectric constant and dielectric loss decreased as increasing frequency explained by Koop’s theory of mechanism. AC conductivity increasing trend observed with frequency, mobility of charge carrier active at high frequency domain.

Rare earth Gd3+-substituted Co spinel nanoferrites structural, dielectric and magnetic properties

Gadolinium-doped cobalt ferrite CoGdxFe2-xO4 (CGF) were produced using citrate gel auto-combustion method (x = 0–0.025 at an interval of 0.005). An investigations on the impact of Gd3+ ions on structural, dielectric, and magnetic properties were conducted. The synthesized materials were characterized using the following techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectroscopy (UV), impedance (dielectric) analysis, and vibrating sample magnetometer (VSM). The crystalline size ranging from 48 to 13 nm. The Williamson-Hall plots were utilized to examine the impact of crystalline size and lattice strain on the peak broadening of each sample. The X-ray diffraction spectra were used to confirm phase identification and spinel structure. The results of FTIR examinations show that strong metal oxide bonds can be found in the tetrahedral and octahedral sites at wavelengths of 351–376 cm−1 and 567–574 cm−1, respectively. The obtained samples to study optical energy bandgap (Eg), which vary from 2.01 eV to 2.45 eV and show that they are semiconducting materials.The Maxwell-Wagner model and Koop's theory have both been used to study the behaviour of dielectric properties. The dielectric constant at room temperature to 673 K in the frequency range 50 Hz–1 MHz to study the dielectric constant, dielectric loss, AC electrical conductivity, and impedance. The impedance charts show how conductivity was impacted by grain and grain boundary mechanisms. In relation to an applied field of 100 kOe, magnetization was measured at 3 K and 300 K. The blocking temperature (TB), which exhibits super-paramagnetic behaviour, is found to be approximately 359 K according to zero-field cooling ZFC and field cooling. The FC experiments carried out in the temperature range of 3 K–360 K under an applied field of 100 Oe.

Structural characterization, optical, and magnetic properties of MgTbxFe2−xO4 nano ferrite particles using a combustion technique

The citrate gel auto-combustion method was utilised to synthesis terbium-doped nanoparticles (NP) with considerable concentrations of magnesium ferrites, using the chemical formula MgTbxFe2−xO4 and an X range of 0.000 to 0.0030 (with an X step of 0.0005). At 300 K, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transition electron microscopy (TEM), and magnetic characteristics were all determined. The XRD and TEM images indicate nanoscale ranges as well as the cubic spinel structure, which is merely phased, and confirm the normal crystallite size. The lattice parameter and volume decrease as density increases with doping of terbium. The images from the FESEM. It is evident that the grain clusters were found within the material. In the specimen's case, the highly interacting grains were found. The fourier-transformed infrared spectroscopy (FTIR) data clearly suggests that two metallic bands have formed, confirming the cubic spinel ferrites. There are two primary absorption bands visible between 200 and 650 cm−1. The UV–vis investigation demonstrates that the calculated direct band gap energy values have a violet shift. The band gab energy was reported in the range of 415.30 eV to 375.12 eV.The magnetic properties of the hysteresis loops indicate a transition from hard magnetic moments to soft magnetic moments. All magnetic properties were reduced when the Tb3+ ion was substituted. They are excellent for switching memory storage devices as well as telecommunications.

Rare earth Gd3+ substituted on cobalt ferrites: Structural and dielectric studies by citrate gel autocombustion method

Gadolinium-doped cobalt ferrite (CoGdxFe2-xO4; X = 0–0.025 in a 0.005 interval) was synthesised using citrate gel autocombustion. The effect of Gd3+ ions on structural, dielectric, and magnetic characteristics has been investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectroscopy (UV), an impedance (dielectric) analyzer, and a vibrating sample magnetometer (VSM) were used to characterise the as-synthesised materials. X-ray diffraction powder patterns were used to confirm phase identification and spinel structure, and the Williamson-Hall plot was used to investigate the crystalline size and lattice strain on the peak broadening of each sample, with crystalline size ranging from 13 to 48 nm. The scanning electron microscopy (SEM) micrographs demonstrate particle agglomeration, while energy dispersive spectroscopy (EDAX) pictures indicate the purity and existence of all elements in the created material samples. The frequency-dependent dielectric constant, dielectric loss, and AC electrical conductivity in the frequency range 50 Hz–1 MHz. The behaviour of dielectric properties has been studied using the Maxwell-Wagner model and Koop's theory. Because of this, higher frequencies show less dielectric loss, making them appropriate for use in high-frequency device applications.

Impact of the Sc3+/In3+ co-substitution on the structural, magnetic, and microwave characteristics of Co0.5Ni0.5Fe2O4 nanospinel ferrites

In this article, In3+ and Sc3+ ions dual-substituted NiCo nanospinel ferrites (ScIn→CoNiFe2O4 NSFs) have been synthesized through citrate-gel auto combustion method to investigate the effect of In3+ and Sc3+ ions on magnetic, and microwave characteristics. The following techniques TEM, SEM, EDX, and XRD were applied to characterize surface morphology, chemical composition, phase identification, and crystallinity of products, respectively. The XRD verified a phase formation of spinel structure with a minor amount of Sc2O3 was observed for products having x ≥ 0.04. The average crystal size (DXRD) of the products was estimated within the 33–68 nm range using the Scherrer equation. SEM and HR-TEM analyses exhibited accumulating sphere-shaped particles. By fitting the room-temperature spectra obtained from Mössbauer spectroscopy (Moss), Hyperfine interactions were determined. The cation distribution shows that there is a migration of In3+ ions in the lattice in an A→B direction with increasing concentrations while the B site is preferred by the larger Sc+3. M−H plots for 300 and 10 K illustrated all products carried out with a ferrimagnetic character. An enhancement in saturation magnetization (Ms) was remarked with Sc–In doping ratio up to 0.04 and thereafter a drop as the Sc–In concentration increased. The tendency in Ms values might be described by correlating it to the cation distribution amongst Oh and Td (octahedral and tetrahedral, respectively) sublattices. Temperature-dependent magnetization measurements were also investigated, which further confirmed the maintenance of the ferrimagnetic character throughout the temperature range 10–300 K. The peculiarities of the microwave properties have been analyzed by the measured S-parameters in the range of 6–18 GHz. It was assumed that the energy losses due to reflection are a combination of electrical and magnetic losses due to polarization processes and magnetization reversal processes in the region of inter-resonant processes. The average value of the reflection coefficient is −14.48 … −14.24 dB. A significant attenuation of the reflected wave energy opens up broad prospects for practical applications as coatings for providing electromagnetic compatibility.

Improvement of the Self-Controlled Hyperthermia Applications by Varying Gadolinium Doping in Lanthanum Strontium Manganite Nanoparticles

In this study, silica-encapsulated gadolinium was doped in lanthanum strontium manganite nanoparticles (NPs) with different concentrations using the citrate–gel auto-combustion method. We focused on tuning the Curie temperature and enhancing the specific absorption rate (SAR) of silica-coated gadolinium-doped lanthanum strontium manganite NPs to make them suitable for self-controlled magnetic hyperthermia. The samples were characterized by using transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and magnetic measurements to examine the structural, optical, and magnetic properties of the manganite NPs. While our results exhibit a successful doping of gadolinium in lanthanum strontium manganite NPs, we further prepared magnetic core NPs with sizes between 20 and 50 nm. The Curie temperature of the NPs declined with increasing gadolinium doping, making them promising materials for hyperthermia applications. The Curie temperature was measured using the magnetization (M-T) curve. Magnetic heating was carried out in an external applied AC magnetic field. Our present work proved the availability of regulating the Curie temperature of gadolinium-doped lanthanum strontium manganite NPs, which makes them promising candidates for self-controlled magnetic hyperthermia applications.

Structural, dielectric, thermoelectric, and magmatic properties of Er3+ ion substituted Mg-Zn spinal nanoferrites: High charge-storage capacitors and high-frequency microwave device applications

The Er-substituted magnesium and zink ferrite nanomaterials with the chemistry formula Mg0.8Zn0.2ErxFe2-xO4 (x = 0.00, 0.005, 0.01, 0.015, 0.02, 0.025) were generated in the study utilizing the citrate-gel auto combustion method. XRD is being used to investigate the cubic spinal structural structure. A transmission electron microscope (TEM) and a field emission scanning electron microscope (FESEM) were used to examine surface morphology. From the structural studies, the crystal sizes range from 14.46 to 96.40, with lattice parameters ranging from 8.434 to 8.449 and X-ray density (gm/cc) ranging from 4.585 to 4.671 and porosity (%) ranging from 7.67 to 7.91. The resulting macrostrain produces internal tension and can impair material grain growth. UV–visible absorption spectroscopy gives grain size pictures as well as quantifications at 300 K and 100 K, respectively. The wavelength range cut-off from 537.6 nm to 270.9 nm. The dielectric characteristics of the samples were tested at room temperature using an LCR meter at various frequencies. The dielectric parameters include the real component of the dielectric constant, the dielectric constant's imaginary portion, and the loss tangent. For each sample, the loss tangent of nanoferrites fell as the frequency increased. This type of material is used in capacitors and microwave devices. Thermoelectric power studies measured all samples. From the studies observed, the seeback coefficient decreases with increasing temperature and Er doping. The room temperature and low temperature magnetic properties were studied at 300 k and 100 k at low temperature ZFC and FC. The blocking temperature Tb was around 300 K.

Characterization of Nano-Structured Magnesium-Aluminum Ferrites Synthesized by Citrate-Gel Auto Combustion Method

An effort is made to find the solution to the new challenges of modification advancements in ferrite technologies. The hypothetical variation in the structural, magnetic, and electrical properties of cubic spinel magnesium aluminum ferrites introduced by the substitution of doping elements has been rationalized and proven. The outcome of aluminum substitution on the magnesium ferrites has been examined and investigated. Spinel ferrites having compositions of MgAlxFe2-xO4 (x = 0.1, 0.2, 0.3, 0.4) were prepared by the sol-gel auto-combustion method. The prepared sample’s characterization, such as scanning electron microscopy (SEM), DC electrical resistivity, AC electrical resistivity, and dielectric properties measurements, were tested using the respective instruments. The grain size and crystal size of all samples were measured from the micrographs of SEM and XRD Data. It is found that the average grain size is within the range of 300 nm - 550 nm for all different series that are formed, keeping the samples at 1100 °C sintering temperatures. A two-probe method experiment with a temperature range of 30 °C to 500 °C gives data on DC electrical resistivity. The Curie temperature depends on the sintering temperature, and it increases with increasing doping concentration. Also, doping influences grain size, which decreases with increasing concentration. Analyzing the SEM micrographs, it is found that the average grain size must decrease in tendency with increasing Al content. DC electrical resistivity exhibits excellent semiconducting behavior. Frequency dependence, dielectric constant, and dielectric loss factors were measured, keeping the frequency range of 75 Hz to 130 MHz at room temperature. The result shows that the dielectric constant (e) and dielectric loss tangent (tan™) decrease with the increase in frequency, while the AC resistivity and Q-factor increase. Comparing the electrical properties of four compositions, it can be suggested that the mixed ferrite, sample-4 (x = 0.3), shows the highest Q-factor of all at 1100 °C.

Effect of neodymium doping on structural, optical, and dielectric properties of Ni ferrites synthesized by citrate gel auto-combustion method

Effect of neodymium doping on structural, optical, and dielectric properties of Ni ferrites synthesized by citrate gel auto-combustion method

Synthesis, structural characterization, optical and electrical properties of NiGdXFe2–XO4 nanoferrites synthesized by citrate-gel auto-combustion method

Synthesis, structural characterization, optical and electrical properties of NiGdXFe2–XO4 nanoferrites synthesized by citrate-gel auto-combustion method

Structural, Frequency and Temperature Dependent Dielectric Properties of Zn2+ Substituted Ni-Co Based Spinel Ferrite (ZnxNi0.8−xCo0.2Fe2O4)

Zinc substituted nickel-cobalt ferrites, i.e., ZnxNi0.8−xCo0.2Fe2O4 (x = 0.0, 0.05, 0.10 and 0.20) with average crystallite size 100 nm were synthesized by citrate-gel auto-combustion method to investigate effects of Zn2+ substitution on the structural and dielectric properties. Both X-ray diffraction (XRD) and IR spectroscopy studies confirms the formation of pure cubic spinel structure. Variation of lattice parameter infers Vegard’s law linear dependence with the addition of Zn2+ concentration. The temperature-dependent behavior of dielectric and modulus spectra has been studied within the frequency range 100 Hz-100 kHz for different temperatures between 100 K and 400 K. It was concluded that the dielectric responses of ZnxNi0.8−xCo0.2Fe2O4 are found to be frequency dependent and thermally activated. Also, In the Zn doped ferrites variations of dielectric loss (tan δ) and the imaginary part of electric modulus (M") show the presence of the non-Debye type of dielectric relaxation. Rise in Zinc concentration leads to a decrease in dielectric constant (ε r) due to the declining of Fe3+–O–M2+ conducting network (M is Co or Ni). Here, we report a low loss tangent factor of the order of for the sample Ni0.6Zn0.2Co0.2Fe2O4 make this composition suitable for high frequency-applications at room temperature. The activation energy is calculated from electric modulus formalism and DC electrical conductivity and found to increase with further substitution of Zn2+ concentration.

Structural, photocatalytic, and anticancer activity Ni-substituted Cu nanochromites synthesized by citrate gel auto-combustion method

Structural, photocatalytic, and anticancer activity Ni-substituted Cu nanochromites synthesized by citrate gel auto-combustion method

Structural, optical, DC electrical, thermo-electric, dielectric and magnetic properties of Mg0.8Zn0.2GdxFe2-xO4 nanoparticles synthesised by citrate-gel auto combustion method

Structural, optical, DC electrical, thermo-electric, dielectric and magnetic properties of Mg0.8Zn0.2GdxFe2-xO4 nanoparticles synthesised by citrate-gel auto combustion method

Al-substituted Mg nanoferrite structural, optical and electromagnetic behaviour prepared via citrate gel auto-combustion method

Al-substituted Mg nanoferrite structural, optical and electromagnetic behaviour prepared via citrate gel auto-combustion method

Structural, photocatalytic, electromagnetic properties of rare-earth metal Gd-doped Mg nanoferrites synthesized by citrate gel auto-combustion method

Structural, photocatalytic, electromagnetic properties of rare-earth metal Gd-doped Mg nanoferrites synthesized by citrate gel auto-combustion method

Structural and dielectric properties of Sr1-xCexMgyFe2-yO4 nano ferrites synthesized by citrate gel auto combustion method

A series of Sr1-xCexMgyFe2-yO4 (where x = y = 0.0, 0.25, 0.50, 0.75, and 1.0) nanoferrites were synthesised via the citrate gel auto combustion method. The synthesised materials structural and electrical properties were examined. Structural properties are investigated by x-ray diffraction analysis (XRD), SEM, and FTIR spectroscopy. X-ray diffraction analysis confirms the cubic spinel structure of the material. The crystalline size of the sample varied from 22 to 32 nm, whereas the lattice parameter was found to be 7.832 to 8.558 Ao. The lattice parameter's linear variation was not observed, which indicates that it does not obey Vegard's law. SEM images reveal those morphological characteristics, which are spherical shapes. EDAX confirms the presence of Sr, Ce, Mg, Fe, and O in the synthesised samples. FTIR spectra confirm the spinel structure with two sublattices, namely, tetrahedral and octahedral sites. Electrical properties carried out by LCR meter at different frequencies and dielectric parameters such as dielectric constant, dielectric loss, AC conductivity, and impedance spectra have been studied. Dielectric constant and loss decreased with increasing frequency, whereas AC conductivity increased. It was explained by the Maxwell-Wagner polarisation theory. A single semicircle type of behaviour was observed in Cole-Cole plots.

Luminescence, photocatalytic and dielectric properties of Sm substituted Mg nano ferrites

Sm-substituted spinel nano ferrites of Mg were synthesized through the Citrate Gel Auto Combustion method. The details of fluorescence, photocatalytic activity, and dielectric studies were investigated. Fluorescence spectra reveal that the emission wave length is at 250 to 380 nm in the region under the excitation wavelength of 220 nm. Photocatalytic activity was carried out by methylene blue and acid red under UV–visible irradiation, and degradation rate obtained every 10 min for 50 min. Dielectric parameters like the dielectric constant, loss, AC-conductivity, and impedance analysis have been studied with variations in frequency and temperature. The sample dielectric constant was decreased upon increasing frequency, whereas AC-conductivity increased. This behaviour is explained by the Maxwell-Wagner polarization theory. Single semicircle behaviour was observed in the impedance spectra.

Optical, luminescence and photocatalytic activity of Sr based Mg, Ce nano ferrites synthesized by citrate gel auto combustion method

The citrate gel method is used to prepare Sr based Mg, Ce nano ferrites series Sr1-xCexMgyFe2-yO4(where x = y = 0.0, to and 1.0 with 0.25 variation). The prepared samples optical, luminescence, and photocatalytic activity have been carried out. Optical properties carried out by UV–Vis’s spectroscopy and the materials optical band gap energy are calculated by formula 1240/λ, which is found to be 1.68 to 2.23 eV. Luminescence properties are carried out by fluorescence spectroscopy. The fluorescence spectroscopy reveals the broad band that appeared from 285 nm. Photocatalytic activity of the synthesized samples is investigated by two organic azo dyes, namely methylene blue and Acid red under visible light. Pure SrFe2O4 catalyst methylene blue degradation efficiency found to be 39.05%. Whereas 55.48 % degradation efficiency found to be x = 0.5 M concentration. For acid red catalytic activity of the SrFe2O4 found to be 39.5 %. The photo decolourization efficiency of organic dye was enhanced by the doping concentration of Ce and Mg content on Sr nanoferrites.

Influence of Cerium substitution on structural, optical, and electrical transport properties of Ni-Nano ferrites prepared by Citrate gel auto combustion method

The citrate-gel auto combustion is chosen to the preparation nanocrystalline materials of NiCeXFe2-X O4(X = 0.0 to 0.040 with variation of 0.010). XRD confirmed the crystalline phase of the prepared samples, and by using Debye Scherrer equation the crystalline size was calculated to be 26–14 nm. Lattice parameter variation was observed for the series of samples, which indicates that it obeys Vegard's law. Agglomerated structures and particles observed in the SEM images are in the nanometre region. Two FTIR bands were found in the FTIR spectrum, which attribute the stretching frequencies of tetrahedral (1) and octahedral (υ2) bands, respectively. The Urbach energy of the present Ce doped Ni NFs was found to decrease with increase in the Ce dopant content. It is an indication that enrichment of rare-earth oxide into ferrite base results in more order and decrease of disorderness. Dielectric studies of the samples carried out by LCR meter, analysed results of AC conductivity (σAC), impedance(Z), dielectric constant (ε/), dielectric loss (Tan δ). The σ AC of the samples increased with increasing temperature and dopant concentration. Impedance spectroscopy revealed semi-circular behaviour, and the effect of grain and grain boundaries on electrical conductivity was investigated. The dielectric permittivity and loss decreased as increasing frequency, which phenomena was explained by Koop’s theory of mechanism.