Substituted Nickel Ferrite Research Articles

Synthesis and characterization of Cu and Tb substituted NiFe2O4@MXene nanocomposite as a new photocatalyst for removal of organic dyes and drugs from industrial wastewater

The study aimed to establish a correlation between the photocatalytic degradation of Congo red (CR), Crystal violet (CV) dyes and Diclofenac sodium (DS) drug by copper, terbium substituted nickel ferrite (CuxNi1-xTbyFe2-yO4) and MXene (CTNF/MXene) composite where (x, y = 0.1). Terbium and copper doping reduced crystallite size, band gap energy, improve visible light absorption and impede electron-hole pair recombination. Superior complexation ability of terbium forces more pollutants to adsorb on the surface of photocatalyst and hence more degradation. Results indicated that MXene, acting as a co-catalyst, effectively lowered the charge recombination rates by electron trapping and enhanced the visible light absorption, improving the photocatalytic activity. CTNF/MXene composite exhibited greater rate constant and photocatalytic degradation of CR (91 %), CV (77 %) and DS (81 %) as compared to NF, CNF, TNF, CTNF. The increased surface area of CuxNi1-xTbyFe2-yO4 with MXene and reduced electron-hole pair recombination are possible factors for its successful use as photocatalyst.

Electric field tuning of a nickel zinc ferrite resonator by non-linear magnetoelectric effects

The nature of nonlinear magnetoelectric (NLME) effect has been investigated at room-temperature in a single-crystal Zn substituted nickel ferrite. Tuning of the frequency of magnetostatic surface wave (MSSW) modes under an applied pulsed DC electric field/current has been utilized to probe the effect. The frequencies of the modes at 8–20 GHz were found to decrease by ~ 400 MHz for an applied DC power P of ~ 100 mW and the frequency shift was the same for all of the MSSW modes and linearly proportional to P. A model is proposed for the effect and the NLME phenomenon was interpreted in terms of a reduction in the saturation magnetization due to the DC current. The decrease of magnetization with applied electric power, estimated from data on mode frequency versus P, was − 2.50 G/mW. The frequency tuning efficiency of the MSSW modes due to NLME effects in the ferrite resonator was found to be 4.1 MHz/mW which is an order of magnitude higher than the shift reported for M-type strontium and barium hexaferrite resonators investigated earlier. The spinel ferrite resonator discussed here has the potential for miniature, electric field tunable, planar microwave devices for the 8–20 GHz frequency range.

Structural Interpretation of Sintering Temperature Effect on Optical and Electrical Properties of Pr3+‐Substituted Nickel Ferrites

Herein, the sintering temperature effect on various properties of Pr3+‐substituted nickel ferrites prepared through the sol–gel–citrate autocombustion method is presented. The Rietveld refinement of X‐ray diffraction patterns confirms the formation of the inverse spinel nickel ferrite phase with an additional orthorhombic phase PrFeO3. The crystallinity of those samples is better with a lesser weight percentage of the secondary phase for higher sintered samples. Structural parameters like crystallite size, lattice parameter, microstrain, and bond lengths depend strongly on sintering temperature with an increasing trend. Scanning electron micrographs clearly show the grain growth of the samples with sintering temperature with the formation of a secondary phase at the grain boundaries. The photoluminescence study points to the photocatalytic nature of the compositions. The bandgaps of the samples are calculated using a UV–vis study, which shows an initial decrease in values with increasing sintering temperature. The electrical study confirms the grain and grain boundary contribution to the total conductivity. With higher sintering temperatures, activation energies decrease, but the dielectric loss and saturation dielectric constant tend to increase. The scaling of conductivity and dielectric loss spectra confirm the time–temperature superposition principle.

Influence of gadolinium doped in nickel nanoferrites on structural, optical, electrical, and magnetic properties

The sonochemical reaction approach was used to make NiGdxFe2-xO4 nanoferrites (x = 0.01, 0.03, 0.05, 0.07, and 0.09). X-ray diffraction (XRD), ultra violet-diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometer, and electrochemical impedance spectroscopy were used to investigate the optical, magnetic, electrical, and structural properties of NiGdxFe2-xO4 nanoferrites. The creation of a cubic spinel structure was confirmed by analyzing the XRD pattern of these NiGdxFe2-xO4 nanoferrites. The average crystallite diameters of the nanoparticles for the compositions x = 0.01, 0.03, 0.05, 0.07, and 0.09 were 57, 53, 48, 45, and 41 nm, respectively. To investigate the dielectric behavior of the produced nanoferrites, an impedance study was performed. The addition of Gd to NiFe2-xO4 nanoparticles increased the dielectric characteristics of the produced nanoferrites, according to characterization experiments. A cation distribution has been proposed for the determination of various important theoretical parameters for these samples. The addition of Gd3+ nanoparticles has shown the ferromagnetic behavior at room temperature confirmed by VSM analysis. A specific correlation between magnetic interaction and lattice strain was observed in Gd3+ substituted nickel ferrite. An increase in Gd concentration in the manufactured nanoferrites resulted in a rise in saturation magnetization and a decrease in coercivity.

Role of neodymium substitution on the structural, magnetic and microwave absorbing properties of nickel ferrites

The neodymium substituted nickel ferrites with a nominal composition of NiNdxFe(2-x)O4 (with x = 0.00; 0.01; 0.03; 0.05; 0.06; 0.08 and 0.10) were successfully synthesized by milling technique. The NiO, Nd2O3 and Fe2O3 powders were used as raw materials and were prepared in a mole ratio. The characterization of the samples was done by X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). In this study, the PXRD showed and verified that all Nd3+ ion successfully substituted the NiFe2O4 samples with a single cubic spinel phase. Infrared spectra showed two strong absorption bands in the frequency range of 405–420 cm−1 and 595–610 cm−1, which were respectively attributed to tetrahedral and octahedral sites of the spinel ferrites. The SEM revealed homogenous morphology on all NiNdxFe(2-x)O4 but still not uniform powders. The particle size of the powder ranged from 150 to 700 nm. The magnetic properties of all of the samples showed a ferrimagnetic behavior. The Ms value was decreased when the Hc increased with increases in the Nd3+ substitution value. The ability to absorb the microwave measured by VNA shows the enhancement of the microwave attenuation where the Nd3+ substitution increased. The microwave attenuation changes increased from 91.25% to 98.32%. It can be seen that the composition of x at 0.05 promises to be new material for microwave absorption.

Substituted nickel ferrite coated MWCNT/PVDF based epoxy nanocomposite for microwave absorption

Metal-substituted spinel ferrite-based microwave absorbing materials (MAMs) are attracting significant attention due to their varied soft magnetic behaviour, and ease of synthesis. This work established the efficiency of Cd2+ substituted nickel ferrite coated MWCNT (with varied MWCNT loading) for X-band microwave absorption, in the presence of PVDF. The substituted ferrite was prepared with a facile solvothermal process. X-ray diffraction and vibrating sample magnetometer analysis confirmed the spinel structure of substituted ferrites and tuned magnetic behaviour of Cd2+ substituted ferrite structure, respectively. FESEM revealed a uniform coating of substituted ferrite on MWCNT and XPS confirmed Cd2+ substitution. Hybrid nanocomposites of ferrite coated MWCNT with PVDF, in the epoxy matrix, revealed superior microwave absorption for NiF-150_10 PV and CdNiF-150_10 PV with an absorber thickness of 3 mm in the X band. The absorption bandwidth with the RL below −10 dB reached 3.9 GHz and 3.6 GHz for NiF-150_10 PV and CdNiF-150_10 PV, respectively. The microwave absorption mechanism was discussed in detail. The developed NiF-150_10 PV and CdNiF-150_10 PV composites can be used as lightweight, low thickness microwave absorbers in the defense and telecommunication industries.

Effect of aluminum substitution on structural and magnetic properties of nickel ferrites: Raman and 57Fe IFNMR studies

We present the structural and magnetic characteristics of Al substituted nickel ferrites NiFe2-xAlxO4 (x = 0.0–0.3) produced through auto combustion. The phase purity and lattice parameters are determined using X-ray diffraction measurements and rietveld refinement analysis respectively. Magnetic investigations demonstrate that when the Al3+ concentration increases, the saturation magnetization (MS) decreases. Raman investigations revealed that the peaks corresponding to the A and B-site sites intensified as a result of Al3+ replacement. Furthermore, 57Fe Nuclear Magnetic Resonance investigations show that after Al3+ replacement, the centre frequencies corresponding to the A- and B-sites shift to lower frequency levels. The Fe site occupancies at the A and B sites are calculated using the findings of XRD, Raman, and NMR experiments, all of which are concurrent with each other. Based on present findings, Al3+ preferentially occupies the B-site over the A-site in nickel ferrite.

Neutron diffraction study and temperature variation of magnetic anisotropy in Bi substituted nickel ferrite

Bismuth doped NiFe2O4 (NFO) polycrystalline samples: Ni1-xBixFe2O4 with x = 0.00, 0.05 and 0.10, were synthesized using solid-state reaction method. The crystal structural, magnetic structure and magnetic properties of parent NFO and Bi-doped NFO samples were characterized using X-ray diffraction (XRD), neutron powder diffraction (NPD) and magnetization (M) versus magnetic field (H) isotherms, respectively. Rietveld refinement of XRD and NPD patterns confirms the formation of a single-phase cubic spinel crystal structure. No observable change in the lattice parameter was found (within the error limits) with the 5 at % Bi doping to NFO, whereas ≈0.15% change in the lattice parameter was observed in case of 10 at % Bi-doped NFO. Room temperature magnetic structure studies using NPD reveal a net magnetic moment of 1.55(3) μB/f. u., in the case of NiFe2O4. The net magnetic moment at room temperature changes to 1.61(4) μB/f.u. and 1.47(5) μB/f.u. for Ni0.95Bi0.05Fe2O4 and Ni0.90Bi0.10Fe2O4, respectively. The same observation was also inferred from the spontaneous magnetization (Msp) obtained from approach-to-saturation (ATS) analysis of M-H isotherms. Temperature (T) dependence of Msp follows a T2 decline. Approximately 14% increase in magnetic anisotropy was observed in Ni0.95Bi0.05Fe2O4 compared to NiFe2O4 in the temperature range 5 K -300 K.

Synthesis and analysis of low field high magnetostrictive Ni-Co ferrite for magneto-electric energy harvesting applications

Low field high magnetostrictive cobalt substituted nickel ferrites with composition Ni1-xCoxFe2O4 (x = 0, 0.25, 0.5, 0.75 and 1) were synthesized by sol gel technique. The formation of cubic spinel structure of samples was confirmed by X-ray diffraction. Surface morphology and optical properties were studied by using scanning electron microscopy and Differential Reflectance spectroscopy. The systematic change in the Metal-Oxygen (M−O) bands with Co substitution in nickel ferrite samples was observed in Fourier Transform Infrared spectra. With Co substitution remanance and coercivity values were increased and Curie temperature values were decreased systematically. The magnetostriction was found to increase with the substitution of Co from 10 ppm to a maximum value of about 200 ppm. Ni0.5Co0.5Fe2O4 showed magnetostriction of ∼−63 ppm at 1500 Oe and ∼−85 ppm at 2000 Oe and strain sensitivity value 1.74x10-9A-1m at 1500 Oe.

Electrical and structural properties of zinc substituted nickel ferrites synthesized by sol-gel technique

Electrical and structural properties of zinc substituted nickel ferrites synthesized by sol-gel technique

Porous hollow nanorod structured chromium-substituted inverse spinel compound: An efficient oxygen evolution reaction catalyst

Spinel-based oxygen evolution reaction (OER) catalyst using various cation substitution strategies is gained importance due to its improved catalyst performance. Herein, we report the chromium (Cr)-substituted nickel ferrite, inverse spinel compound (NiCrFeO4) of porous hollow nanostructure using a simple electrospinning approach. The developed inverse spinel compound displays a nanorod-shaped nanostructure of an overall diameter of 60 ± 10 nm and an inner hollow thickness of 30 ± 10 nm. In this study, the Cr-substituted catalyst delivers an overpotential value of 298 mV which is lower than the developed electrospun-based Cr-free NiFe2O4 (330 mV) and the commercial-based NiFe2O4 (330 mV) compound at 10 mA cm−1 under 1 M KOH. Further, the Cr-substituted catalyst exhibits a low Tafel slope value of 44.7 mV dec-1 than the RuO2 catalyst (63.7 mV dec-1). In addition, the catalyst is able to deliver excellent OER durability of 14 hrs at voltage retention of 94.5 % at 10 mA cm−2 condition. In this study, a simple method and a favorable nanostructure to unveil a potential OER candidate are developed.

Synthesis, structural and magnetic properties of NiFe2–xLaxO4 (0 ≤ x ≤ 0.10) nanoparticles

Lanthanum substituted nickel ferrites NiFe2–xLaxO4 (0 ≤ x ≤ 0.10) powders have been synthesized for the first time by combustion technique using glycine as a fuel. All the ferrites crystallize in $$ Fd\overset{\_}{3}m $$ space group with cubic symmetry. Very small peaks of both Fe2O3 and LaFeO3 were also detected, the intensity of which increases with increasing La content. No systematic trend in the lattice parameter a with La doping has been noticed. Room temperature magnetization studies, obtained from vibrating sample magnetometer (VSM), exhibit a decrease in saturation magnetization with La doping. Cation distribution, obtained from magnetic measurements, shows that La doped nickel ferrites have inverse spinel structure in which Ni2+ ions predominantly occupy octahedral sites.

Effect of Sr2+ Ion–Substituted Nickel Ferrite Nanoparticles Prepared by a Simple Microwave Combustion Method

Microwave combustion technique (MCT) was used to synthesize of spinel Ni1-xSrxFe2O4 (x = 0.0, 0.1, 0.3 and 0.5) nanoparticles (NPs) by employing the fuel L-arginine. The physical characteristics of the as-prepared NPs were obtained by following methods, viz., powder X-ray diffraction (XRD), high-resolution scanning electron microscope (HR-SEM), energy-dispersive X-ray (EDX), UV-visible diffuse reflectance spectra (UV-Vis DRS), Fourier-transform infrared spectra (FT-IR), and vibrating sample magnetometer (VSM) techniques. The diffraction studies revealed that the average crystallite size exists in the band of 14.25 to 27.52 nm. The HR-SEM pictures revealed the agglomerated and spherical morphology of spinel Ni1-xSrxFe2O4 (x = 0 to 0.5) nanoparticles. Elemental analysis ensured the existence of Ni, Sr, O, and Fe ions. The energy band gap of the NPs was observed to exist in the range of 2.95 to 3.39 eV upon varying the concentration of Sr2+ dopant. The broad peaks at 437 cm−1 and 582 cm−1 correspond to octahedral (B-) metal stretching (Ni-O) and tetrahedral (A-) metal stretching (Fe-O) of nickel ferrite respectively. Magnetic results revealed that the prepared NPs are ferromagnetic in nature. The antibacterial activity (ABA) of gram-positive Staphylococcus aureus and Bacillus subtilis and gram-negative Escherichia coli and Klebsiella pneumonia has been investigated using pure and Sr2+-substituted NiFe2O4 NPs. It was found that the improved activity is intensified with smooth Sr2+ doping as it causes a decrease in the grain size.

Cd-Gd-doped nickel spinel ferrite nanoparticles and their nanocomposites with reduced graphene oxide for catalysis and antibacterial activity studies

During the past few decades, rapid industrialization of the world communities and over use of antibiotics in the medical field have badly influenced our natural ecosystem. Now, these ever-worsening issues have succeeded in drawing the attention of the researchers. In this connection, we have fabricated binary metal substituted nickel ferrite (Ni0.96Cd0.04Gd0.04 Fe1.96O4, NCGF) and its nanocomposite with r-GO via wet chemical method. The photocatalytic and antibacterial aptitude of the fabricated samples have been tested and compared by using organic pollutants (Methylene Blue and Rhodamine-B) and bacterial strains (Escherichia coli and Staphylococcus aureus), respectively as a representative. The nanocomposite showed better photocatalytic and antibacterial aptitude than that of pristine NCGF. More precisely, the NCGF/r-GO heterojunction based photocatalyst degraded 92.27% methylene blue (MB) dye and 53.18% Rhodamine-B (Rh–B) dye under visible light irradiation. In comparison, the NCGF photocatalyst degraded just 20.25% MB and 11.93% Rh–B dye under the same conditions. The higher activity of NCGF/r-GO photocatalyst is accredited to the suppression in the recombination process of the charge carriers caused by the addition of r-GO in the NCGF matrix. Moreover, the NCGF/r-GO photocatalyst retained 92% of its initial catalytic efficiency even after 5-recycles that indicate its higher stability and good reusability. Additionally, the NCGF/r-GO sample exhibited superior antibacterial aptitude than that of the pristine NCGF sample toward the E. coli and S. aureus bacteria. In fact, the primary constituent of the bacterial cell wall are organic compounds, lipopolysaccharide and peptidoglycan, that are also labile to degrade via photo-induced reactive oxygen species (HO•,O‾2•&H2O2 ). The leakage of K+ ions from the raptured cell wall, stop the crucial cell functions that result in the death of the whole bacterial cell. This work offers new insights for the fabrication of substituted ferrites nanomaterials for environmental protection and ecological safety.

Microwave Assisted Synthesis of Chromium Substituted Nickel Ferrite Spinel for Oxygen Evolution Reaction

Herein, a simple microwave assisted combustion approach is utilized for the synthesis of nano-sized Cr substituted Ni ferrites (NiCr x Fe 2-x O 4 ). The as obtained materials were further sintered at 450°C in air and then utilized for physicochemical and electrochemical characterizations. X-ray diffraction (XRD) patterns showing sharp peaks confirmed the formation of single phase cubic spinel structure. TEM image reveals the formation of nanocrystalline particles having size in range of 10-20 nm. Further, the electrocatalytic oxygen evolution reaction (OER) of as-synthesized materials was studied by linear sweep voltammetry in alkaline solution. The OER results showed that co-substitution of Cr in NiFe 2 O 4 matrix improved the electrocatalytic activity of the oxides towards OER. The NiCr 0.5 Fe 1.5 O 4 shows the best OER performance in 1.0 M KOH solution. It achieved a low overpotential of about 320 mV at 10 mA/cm 2 current density, which is comparable to other reported electrocatalysts. Tafel parameters and order of reaction were also in close agreements with literature values. DOI: http://dx.doi.org/10.17807/orbital.v12i3.1507

Comprehensive study on structural, electrical, magnetic and photocatalytic degradation properties of Al3+ ions substituted nickel ferrites nanoparticles

A series of Al3+ substituted NiAlxFe2-xO4 (0.0 = x ≤ 0.5) nanoparticles was synthesized using the chemical co-precipitation route. The effect of Al3+ ions doping was investigated in terms of structural, degradation, magnetic and electrical properties of the nanoparticles (NPs). The XRD patterns confirmed the formation of the spinel cubic phase. FT-IR spectra revealedtwo consistent absorption bands indicating the intrinsic stretching vibrations of O2- Fe3+ around 591-615 cm−1 and 416-428 cm−1 bond lengths for tetrahedral and octahedral sites respectively. The magnetic properties decrease as the concentration of Al3+ increases. The decrease of magnetic parameters can be explained by the difference between magnetic moments of Al3+ and Fe3+ cations. Maxwell-Wagner model of space charge polarization was utilized to explain the dielectric properties with frequency. The increasing dielectric losses indicated the suitability of synthesized NPs for microwave absorption, telecommunication, electronics and other high frequency applications. The dependence of dielectric properties on grains and grain boundaries was further investigated via impedance spectroscopy and complex electric modulus. The study of photo-degradation efficiency of NPs was performed using organic methylene blue dye. The results showed satisfactory degradation with maximum degradation efficiency of 84.45% for NPs with composition NiAl0·5Fe1·5O4.

Structural and magnetic properties of Bi substituted nickel ferrite

Abstract Polycrystalline Ni1-xBixFe2O4 (x = 0.00, 0.05 and 0.10) are prepared by a solid state method. The crystal structure, and magnetic properties are investigated using XRD, Raman and VSM magnetometer. The material formed in the cubic inverse spinel phase without any impurity from XRD. A small distortion of the cubic lattice is observed upon the substitution of Ni by Bi in the A site. The lattice parameter (a) changes non monotonically, first increases then decreases with Bi doping content. From Raman measurements, Raman modes match with the typical modes of cubic inverse spinel ferrite structures belonging to the Fd 3 - m space group. The gradual shifts in wave numbers indicate that the Bi3+ substitutes for Ni3+ at the A-site. The Ms Values of the Ni1-xBixFe2O4 compounds are found to decrease with increasing for 5% doped Bi sample and again increase for 10% Bi doped sample. The Curie temperature TC values of Ni1-xBixFe2O4 are 871, 875 and 885 K, for x = 0.0, 0.05 and 0.1 respectively. It is important to note that the TC value increases in Bi -substituted nickel ferrites compared to pure nickel ferrite.

Fabrication of Ce3+ substituted nickel ferrite-reduced graphene oxide heterojunction with high photocatalytic activity under visible light irradiation

In the current investigation, graphene (rGO)-supported cerium substituted nickel ferrite (NiCeyFe2-yO4 y = 0.05) photocatalyst was prepared via two-step wet chemical approach. The resulting NiCeyFe2-yO4/rGO nanocomposite exhibited excellent photocatalytic performance and stability. Moreover, the photocatalytic activity of NiCeyFe2-yO4/rGO nanocomposite was also investigated comparatively with NiCeyFe2-yO4 nanoparticles. As compared to the NiCeyFe2-yO4 nanoparticles, NiCeyFe2-yO4/rGO nanocomposite showed superior photocatalytic efficiency and recycling stability for MB degradation, which is two times that of bare NiCeyFe2-yO4 nanoparticles. After visible light irradiation for 70 min, 94.67 % of MB dye was removed by NiCeyFe2-yO4/rGO nanocomposite whereas only 50 % of MB dye was removed by NiCeyFe2-yO4 nanoparticles. The increase in photocatalytic performance is mainly ascribed to formation of NiCeyFe2-yO4/rGO heterojunction which not only assist in separation of photo-induced charge carriers, but also sustain a strong redox ability. Moreover, the photo-corrosion of NiCe0.05Fe1.95O4 nanoparticles is inhibited through transfer of photo-induced electrons of NiCe0.05Fe1.95O4 nanoparticles to rGO. A possible photo-degradation mechanism based on reactive species trapping experiments has been proposed. The effect of various factors like pH, temperature and catalyst dosage has also been explored. Facile synthesis method, excellent photocatalytic performance for organic pollutants and superior reusability suggest that NiCeyFe2-yO4/rGO photocatalyst possesses high potential for large-scale pollutant treatment.

Synthesis and study of Co doped Ni-Cd ferro-spinels by microwave assisted sol-gel auto-combustion method

Cadmium substituted Nickel Ferrite, Ni0.5CoxCd(0.5-x)Fe2O4 (x = 0.0, 0. 02) were synthesized by sol-gel auto-combustion technique with microwaves using urea as fuel. The samples were sintered at two different temperatures 600 °C and 800 °C. This paper discusses the effect of sintering temperature on varius structural, morpological, magnetic and optical properties of the syntesized samples. The structural properties such as crystallite size, lattice constant, lattice strain oxygen position parameters, bond lengths and bond angles. Phase analysis of the sample are carried out using XRD measurement. Surface morphology and qualitative and quantitative chemical composition of the samples were done by FE-SEM and energy dispersive X-ray analysis (EDX) measurements respectively. Magnetic properties such as saturation magnetization (Ms), coercivity () retentivity (Mr), squareness and were obtained from VSM measuements. The variation in the observed and measured magnetic quantities are explained on the basis of YK model.The cation distribution proposed has been discussed based on the observed experimental measured magnetic parameters and it futher discuss spin canting angle and nature of exchange interaction among the magnetic moments of octahedral and tetrahedral sites.

Effect of Cobalt and Nickel Substitution on Structural and Magnetic Properties of Spinel Ferrite

Cobalt substituted Nickel ferrites, Ni1-xCoxFe2O4 where x = 0, 0.6, one were successfully synthesized by sol-gel auto-combustion method. With the help of the XRD machine, the phase formation and structural analysis of the samples have been carried out. The surface morphology has been studied using Transmission Electron Microscopy. The magnetic properties of the synthesized samples were carried out using Vibrating Sample Magnetometer. The lattice parameter was found to be in the range of around 8 Å it is noted that the lattice parameter is varied sample to sample and have been mentioned in this research paper.