Citrate-gel Auto Combustion Research Articles

Rare Earth Nd3+ Doping Cobalt-Cadmium Nanoferrites Structural, Optical, and Magnetic Properties and Applications

Nanoscale particles of neodymium-substituted cobalt-cadmium generic formula for nanoferrite Co0.4Cd0.6NdxFe2−xO4 samples at X = 0.000, 0.003, 0.005, 0.007, 0.009, and 0.011 were studied. The prepared powders were synthesised at low temperatures using citrate gel auto-combustion process. The synthesised powders were calcined at 500 °C for four hours. The morphological properties of the sintered powders were investigated, and their crystal structure was determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD peaks confirmed the spinel ferrite structure. The lattice parameter was calculated from the XRD and showed decreasing trends with 8.442 to 8.308. SEM revealed an irregularly-shaped grain morphology with a homogeneous distribution. Raman spectroscopy analysis showed slight frequency changes in the Raman modes in doped samples, attributed to variations in the cation distribution. The peaks are located at 191, 291, 461, 591, and 671 cm−1. UV spectroscopy studies showed that the energy band gap values decrease with increasing Nd3+ concentration. Direct optical band gap values obtained were 1.238, 1.248, 1.199, 1.135, 1.134, and 1.101 eV with increasing Nd doping. The magnetic hysteresis properties were determined using a SQUID-VSM magnetometer. The hysteresis curves of Co0.4Cd0.6NdxFe2−xO4 nanoparticles show an increase in coercivity with increasing doping concentration. This enhancement is attributed to the multi-domain behaviour.

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 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.

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.

Influence of Er/Fe Substitution on Mg-Zn Nanoparticles’ Electromagnetic Properties and Applications

Mg0.8Zn0.2ErxFe2-xO4 (x = 0.00, 0.005, 0.01, 0.015, 0.02, and 0.025) nanoparticles made using the citrate gel autocombustion process were examined for their structure, morphology, and behavior. The single-phase cubic spinel structure was formed according to the diffraction pattern. Observations revealed that as the Er focus went from to 0.0 to 0.025, the average crystallite size (D) increased from 12.4 to 18.6 nm. The findings of the SEM and EDAX analyses reveal that the particles are uniform, with just a little amount of agglomeration and no impurity pickup. Nanoparticles from transmission electron microscopes (TEM) were present, the range from 12 to 19 nm. In IR spectroscopy using the Fourier transform (FTIR), nearly all the spinel ferrites presented generate two absorption bands that have wavelengths of around 400 cm and 600 cm. The BET surface area of the Er3+ ion doping Zn-Mg ferrites rises from 23.860 m2/gm to 29.845 m2/gm. The TG–DTA analysis of the prepared samples confirms the thermal stability of the samples; the temperature ranges from 100 to 750 °C.The transition temperature (Seebeck coefficient) of the samples was studied using thermoelectric power (TEP) measurement studies, and it was found that all the samples showed N-type semiconductor behavior. With an increase in erbium concentration, DC conductivity decreases. At room temperature, the magnetic characteristics of hysteresis loops, squareness ratio (SQR), anisotropy constant (K), magnetic moment (), coercivity (Hc), saturation magnetization (Ms), and retentivity (Mr) were examined. When erbium concentration rises, the magnetic moment (B) increases. The saturation magnetization values were 288.4615 and 244.5266 emu/g, and squareness ratio values from 0.01554 to 0.03303 were observed. These materials are converted from hard permanent magnet materials to soft magnet materials.

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

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.

P-type semiconductor Gd/Fe ion doped Ni-Mg nanoferrites applications

Citrate gel-auto combustion was used to create gadolinium doped Ni-Mg ferrites with the chemical formula Ni0.8Mg0.2GdxFe2-xO4 (NMGF) with compositions x = (0.00, 0.005, 0.010, 0.015, 0.020, and 0.025). Gadolinium substitution has been studied to see how it affects the structural and electrical characteristics of Ni-Mg complexes. The NMGF crystallizes into a cubic spinel structure, with no secondary phase emerging, according to X-ray diffraction patterns. The elemental composition analysis validates the existence of the predicted components in the samples based on stoichiometry. Images taken with a transmission electron microscope with high resolution and a scanning electron microscope indicate the type of grain formation as well as the particle size of the produced materials. As compared to undoped Ni-Mg ferrite, Fourier transform infrared spectroscopy verifies the establishment of spinel phase and predicts the movement of bands corresponding to Fe-O vibrations towards higher wavenumbers. The samples were measured for conductivity at temperatures ranging from 300 to 723 K. Conductivity measurements revealed the ferromagnetic to paramagnetic transition temperature (Tc) for all materials. The activation energy was determined below and above Tc. TEP measurements of NMGF ferrites were made using a differential technique at temperatures ranging from 300 to 723 K. The prepared ferrites' Seebeck coefficient (S) rose with increasing temperature.

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.

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.

Effect of Sm3+ doped Ni-Cd Nano ferrite synthesis and structural characterization by citrate-gel auto combustion method

Ferrite nano particles of basic composition Ni Cd Smx Fe2-xO4(0.0 ≤ x ≤ 0.05, X=0.01) where synthesized by citrate-gel auto combustion method have investigated. X-ray diffraction profile indicates that the samples are in single phase structure for the sample without Sm content. For the samples with Sm ions, some diffraction peaks appeared which belongs to the orthorhombic phase structure further, the XRD have been used calculated the lattice parameter, density and grain size. The particle size of the starting powder composition varied from 30 nm to 45 nm. The values of lattice parameter (a) decreased and X-ray density (dx) increased with the increase of Sm content. Morphology of the prepared samples by citrate-gel method was studied using scanning electron microscope (SEM). The elemental analysis of all the Ni-Cd-Sm ferrite samples with different compositions was analyzed by Energy Dispersive Spectrometer (EDS). The observed results can be explained on the basis of composition and crystal size.

Structural, optical, magnetic and dielectric properties of Ag doped Mg nano ferrites prepared by citrate gel auto combustion method

The Silver Substituted Magnesium ferrites with the formula MgAgXFe2-XO4 (where 0 ≤ x ≤ 0.5 by step 0.1) have been prepared through the citrate gel auto combustion method. Prepared samples structural, morphological, electrical, and magnetic properties have been investigated by XRD analysis, FESEM, AC conductivity, and VSM respectively. XRD and FESEM were used to investigate the structural properties of prepared ferrite materials such as average crystalline size, lattice parameter, X-ray density, unit cell volume, and morphology. Crystalline size was measured to be between 25–30 nm. Five Raman active modes (A1g+Eg+3Tg) were observed in the Raman Spectrum, which are expected in the spinal ferrite system. The prepared sample's structure is confirmed by FTIR spectra bands appearing ∼400 and ∼600 cm−1 wave number region indicates that stretching frequency of tetrahedral (A-site) and octahedral (B-site) respectively. The optical band gap energy of the material observed ranged from 3.44 to 3.51 eV. The variation of dielectric properties has been studied with regard to temperature variation as a function of frequency. All the samples dielectric constant decreases with increasing frequency and temperature, which is the nature of ferrites. It obeys the Maxwell-Wagner type of dispersion because of interfacial polarization. The magnetic properties investigated by room temperature VSM, low coercivity values observed indicate that the sample is of soft magnetic nature.

Study of structural, optical, photocatalytic, electromagnetic, and biological properties Co0.75Mg0.25CexFe2−xO4 of Mg-Co nano ferrites

Nano spinel ferrites with formula Co0.75Mg0.25CexFe2−xO4 (0 ≤ x ≤ 0.25 by step 0.05) were synthesized by using citrate gel auto combustion method and studied their structural characterization, optical studies, photocatalytic, biological and electromagnetic properties. Structural properties carried out by XRD, SEM, EDS, FTIR spectroscopy. The XRD studies confirm the crystalline size & lattice constant of Ce co-doped Co-Mg mixed nano ferrites. Morphology of the samples were examined by SEM and EDS analysis confirmed the proposed sample composition. FTIR spectral analysis help to confirm the formation of spinel structure in ferrite samples. Further optical studies confirm the band gap energy and cut off wavelength. Photocatalytic degradation of MB and AR dyes were carried out and good results were observed the degradation activity due to the catalyst heat treatment. Antibacterial studies confirmed that the nanoparticles are toxic to Bacillus subtilis, staphylococcus aureus (gram-positive strains) and Escherichia coli, Klebsiella pneumonia (gram-negative strains) Bacillus subtilis showed highest zone of inhibition of 13.3 mm. Saturation magnetization, coercivity, and remanence magnetization were calculated by VSM and Co0.75Mg0.25Ce0.25Fe1.75O4 was found to have high saturation magnetization that indicates that the sample behaves like a super para magnet. The Squareness of Co-Mg-Ce mixed nano ferrites initially decreases than increases hence the system changes from soft ferrites to hard ferrites. The electromagnetic properties such as AC conductivity (σAC), Dielectric constant (ε/), and impedance analysis are reported. The cole–cole plots shows the single semicircle behaviour.

Magnetically separable mixed metal oxide nanocomposite (Pd/MnFe2O4) for Suzuki cross-coupling in aqueous medium

Magnetically separable Pd/MnFe2O4 nanocomposite has been synthesized by coupling palladium with MnFe2O4via citrate gel auto combustion and deposition precipitation method. The physicochemical and microscopic study of Pd/MnFe2O4 was investigated using various characterization techniques. The zeta potential of the prepared nanocomposite Pd/MnFe2O4 was found to be highly negative value of -36.7 mV, which stabilizes the particle in its dispersed state and also helps to polarize the aryl-halide bond. The catalytic activity of Pd/MnFe2O4 was explored for Suzuki cross-coupling of aryl boronic acids and aryl halides (I, Cl, Br) in an aqueous medium. Interestingly, the rate of the slow oxidative addition step of the reaction is enhanced due to the high negative surface charge of the catalyst. It is worth mentioning that high turnover number (TON) and turnover frequency (TOF), thermal stability, ease of handling, nontoxic, magnetically separable, and recyclable are the remarkable properties of the present catalyst. Moreover, the protocol was found to be significant with respect to reaction time, substrate scope, the yield of products, and solvent used for the reaction.

Impact of erbium (Er) doping on the structural and magnetic properties of Ni-Cu (Ni0.1Cu0.9Fe2O4) nanoferrites

Rare earth erbium (Er) doped spinel Ni-Cu nanoferrites having chemical composition Ni0.1Cu0.9ErxFe2-xO4 (x = 0.00, 0.010, 0.015, 0.020, 0.025 and 0.030) were prepared by standard citrate-gel auto combustion (CGAC) technique. X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, and vibrating sample magnetometer (VSM) were used to characterize the structural, optical, and magnetic properties of these ferrites. X-ray diffraction spectra clearly revealed that the pure Ni-Cu ferrite shows a tetrahedral distortion due to John Tellar ion (Cu2+) subsequently erbium doping transformed the tetragonal phase in to the cubic spinel phase with minor traces of impurity phase. Using Scherer's equation, the average crystallite size was found to be between 7.39 and 27.78 nm. The average crystallite size (7.39–27.78 nm) obtained from XRD and average grain size (64.84–83.36 nm) measured from FESEM confirmed the nano structure of prepared samples. Energy dispersive analysis X-ray (EDAX) spectra with elemental analysis verified the existence of Ni, Cu, Er, Fe, and O elements without any impurities. Two prominent absorption bands detected in FTIR spectra within the wave number range of 575.54–586.73 cm−1 (υ1) and 370.24–372.53 cm−1 (υ2) indicate the stretching vibrations of Fe3+-O2− complexes in tetrahedral and octahedral sites of spinel structure respectively. TG and DTA techniques were used to analyze the thermal behavior of the composition x = 0.030. It was observed that exhibiting a rapid loss in weight after 900 °C promotes the formation of pure phase nanoferrite. Direct and indirect optical band gap values were computed from UV absorption studies with Tauc plots. The obtained band gap values revealed the semiconducting behavior of the prepared samples. VSM was used to explore the magnetization of samples as a function of field at temperatures of 15 K and 300 K. The maximum saturation magnetization (Ms) was observed for x = 0.030 composition and it was estimated as 31.18 emu/g at 15 K and 26.80 emu/g at 300 K temperatures. The experimental and theoretical values of lattice parameter and room temperature magnetic moment are good agreement with suggested cation distribution.

Synthesis, structural, photocatalytic and anti-cancer activity of Zn doped Ni nano chromites by citrate gel auto combustion method

Nano structured zinc doped nickel chromites Ni1-xZnxCr2O4 (where 0 ≤ x ≤ 1 by step 0.2) were fabricated by the citrate gel auto combustion route and were characterized with several techniques like XRD, SEM, EDS, Transmission Electron Microscope (TEM), FT-IR, UV–Vis and Photoluminescence. A formation of single-phase cubic structure and the crystalline state of fabricated samples in size range of 9-to–20 nm were established by the X-ray diffraction studies. The SEM images have revealed the shape of Ni substituted Zn nano chromite. The existence of Ni, Zn, Cr and O in the series of samples were also confirmed by the elemental analysis (EDS) study. FTIR spectra revealed the formation of metal oxide bands and spinel chromite structures which have tetrahedral and octahedral stretching frequency bands. Using the UV–Vis spectrometer, the optical properties of Ni-Zn chromite has been studied and also have that the band gap energy of Ni chromite (3.54 eV) is smaller than that of Zn chromite (3.85 eV). The optical band gap energies were found to be 2.10–3.08 eV for the direct band gap calculated from Tauc plots. The present study mainly focused on the photo-degradation of methylene blue and acid red on the Ni-Zn chromite’s under UV light. The chromites have shown good and clear degradation at certain time intervals with the reference. The biological activity of the synthesized Ni-Zn chromites were performed for their anticancer activity on Hela cell lines and all the molecules exhibited with different IC50 values ranging from 21.83 to 74.15.