Cobalt Ferrite Nano Research Articles

Reitveld refinement, structural, optical band gap and low-temperature magnetic characterization of Gd3+ doped spinel cubic CoFe2O4 nanoparticles

The current study unravels the structural, optical band gap and magnetic characteristics of rare-earth (RE) gadolinium (Gd) substituted CoGdxFe2-xO4 (x= 0.00 - 0.10, in the interval of 0.02) nanocrystallites synthesized by the sol-gel self-ignition route. The XRD analysis and Rietveld refinement confirmed the existence of a single cubic phase with a crystallite size of ~15-21 nm range, further confirmed by HRTEM results. SEM images confirmed the well-known nano-size morphology for all the samples. The magnetization measurements show a hard ferromagnetic nature for all specimens within the temperature range of 20-300K. Coercivity, remanent, and saturation magnetization monotonically increased with a reduction in temperature from 300K to 20K. UV-Vis absorbance results show that the band gap energy of CoFe2O4 nanoparticles (NPs) decreases with increasing Gd3+ ion doping and have band gap energy values of 2.47, 2.15, 2,02, 2.00, 1.43 and 1.95 eV for x= 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, respectively in CoGdxFe2-xO4 nanoferrites. The present study reveals that structural, optical band gap and magnetic properties could be altered by monitoring the quantity of gadolinium in cobalt nanoferrites.
 Bangladesh J. Sci. Ind. Res. 57(3), 173-186, 2022

Study of electronic structure and dielectric properties of Gd-doped cobalt nanoferrites

Study of electronic structure and dielectric properties of Gd-doped cobalt nanoferrites

Effect of calcination temperature on structural, antibacterial, radiation shielding and magnetic properties of cubic spinel cobalt nanoferrite

For the first time, Cobalt ferrite (CoFO) nanoparticles (NPs) were synthesized by solution combustion method using BigThyme leaf extract as a reducing agent followed by varying the calcination temperature as-formed — 800 °C. At all the calcination temperatures, Bragg reflections matches well with FCC cubic spinel structure. Crystallite size increases from 12–79 nm with increase in calcination temperature. The SAED pattern and d-spacing from Transmission electron microscopy matches well with the PXRD pattern and the calculated crystallite size matches well with the Scherrer’s formula. The direct energy band gap was found to be 1.55 eV. The effect of calcination temperature on different magnetic properties such as retentivity, coercivity, saturation of magnetization, squareness ratio and Bohr magneton was discussed in detail. Large coercivity (2.26 kOe) is observed at low calcination temperature. Further, X-ray/gamma radiation absorption parameters such as mass attenuation coefficient, half value layer and Zeff are established which is an essential in the field of radiation dosimetry. CoFO NPs exhibited sensitivity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The cytotoxic properties were examined on cervical cancer HeLa cells and compared with the cisplatin drug. CoFO NPs shows higher % cell viability and less % cell death. Thus, CoFO NPs can be used as a drug carrier in cancer therapy.

Amalgamation and Characterization of NiCo Ferrite by using Sol-gel Auto Combustion Technique

The effect of Nickel doped Cobalt ferrite nano particles Ni0.2CoxFe2-x04(x=0.1, 0.2, 0.3, 0.5) Created by sol-gel auto combustion technique by using citric acid as fuel. The single phase cubic structure form confirm by the XRD. The crystalline size calculated by FWHM of (311) plane using Scherer’s formula. The typicalsize of the crystalline sample varies in the order of nano regime. The structural and lattice parameter were obtained by XRD data. The surface morphology of Nickel doped Cobalt ferrites was studied by Field Emission Scanning Electron Microscope (FESEM), and Scanning Electron Microscope (SEM) images. The spherical particles with the average grain size 25.62nm to 33.69nm range are observed by FESEM images. Compositional stoichiometry was confirmed by X-ray photo electron spectroscopy.

Synthesis and characterization of non-stoichiometric cobalt nanoferrites for multifunctional applications

Synthesis and characterization of non-stoichiometric cobalt nanoferrites for multifunctional applications

Cobalt Nanoferrites: a Review on Synthesis, Characterization, and Applications

Cobalt Nanoferrites: a Review on Synthesis, Characterization, and Applications

Correction to: Investigation of cationic distribution, Y–K angles, and optical and dielectric properties of as-synthesized cerium-doped cobalt nano-ferrites prepared by co-precipitation method

In this article Muhammad Danish ali at University of the Punjab Lahore was missing from the author list.

Investigation of cationic distribution, Y–K angles, and optical and dielectric properties of as-synthesized cerium-doped cobalt nano-ferrites prepared by co-precipitation method

Investigation of cationic distribution, Y–K angles, and optical and dielectric properties of as-synthesized cerium-doped cobalt nano-ferrites prepared by co-precipitation method

Adsorption Isotherms and Kinetics of the Adsorption of Rare Earth Elements {La(III)&Pr(III)} by Nanocobalt Ferrite

Background: Thermal decomposition of metal oxalates, which lead to transition metal oxide composite, is considered to be a versatile method for the synthesis of transition metal oxide composite and its extraordinary applications. Objectives: Nanometal oxide composite, especially, nanocobalt ferrite (CoFe2O4), is prepared efficiently in a simple, eco friendly and cost effective manner. Various characterization techniques like XRD, FTIR, SEM and EDS are applied to explore the morphology, functional groups, bonding nature and size of the nano particles synthesized. Adsorption of rare earth elements La(III) and Pr(III) onto synthesized nanocobalt ferrite is further studied using ICPAES method. Methods: Here, authors make an attempt to exploit meso porous CoFe2O4 synthesized through thermal decomposition method and exploited it as an adsorbent for the adsorption of REEs, namely Lanthanum and Praseodymium in their trivalent oxidation state La (III) & Pr (III) using ICPAES technique. Results and discussion: The influencing parameters such as the adsorption efficiency, which include equilibrium time, pH, initial rare earth element concentration, adsorbent dosage and effect of temperature are studied. Adsorption isotherms, kinetics and thermodynamic parameters are analyzed. Conclusion: It is observed that adsorption studies follow pseudo second order kinetics and follow adsorption isotherms of Langmuir. The adsorption capacity is observed to be more than 90%.

Promising solar photodegradation of RY 86 by hydrophilic F127 (pluronic) aided nano cobalt ferrite and its biomedical applications

To our surprise, we effectively excelled in developing the hydrophilic, non-ionic and water soluble triblock copolymer surfactant F127 (pluronic) aided spinel cobalt ferrite (CFO) nanoparticles. The crystalline nature and surface morphology of F127 aided CFO nanoparticles have been confirmed laboriously by XRD, HR-TEM, DLS, FT-RAMAN, FT-IR, UV-DRS, and SEM-EDX. SEM confirms undeclared rod-like structure and HR-TEM supports a shape similar to quasi-spherical morphology. The band gap investigation report that the Eg value of F127 aided CFO is around 1.24 eV. We found the fact that, in the UV/solar light degradation of hazardous Reactive Yellow 86 (RY 86), the photocatalytic activity of F127 aided CFO nanoparticles was accelerated by the presence of H2O2. F127 is a surfactant that played a key role in the enhanced activity of F127 aided CFO nanoparticles. By using an external magnetic field, the catalyst can be recovered from the fluid medium and thereby reused. The feasible mechanism for active liquid phase photodegradation of RY 86 has also been developed. Therefore, we assure that the novel spinel F127 aided CFO nanoparticles will shed more light for the wastewater treatment system because of its effective photocatalytic and reusable behavior. In conjunction, the antibacterial function and cytotoxicity are also performed.

Co-Existence of Experimental and Theoretical Studies of Ag Substituted Cobalt Nano Ferrites

Co-Existence of Experimental and Theoretical Studies of Ag Substituted Cobalt Nano Ferrites

Facile integration of a novel Sm-doped CoFe2O4@ g-CN heterostructure to expedite PMS and H2O2 assisted degradation of pharmaceutical pollutants

The persistence of pharmaceutical compounds in the aquatic system has cascading effects on environment and the living world. In order to address the grave concerns regarding pharmaceutical pollution, samarium (Sm) doped cobalt nanoferrite (CS) was merged with a π conjugated carbonaceous material i.e. graphitic carbon nitride (g-CN) to form a series of heterojunction nanocomposites, (CS@x%g-CN) via ultrasonic assisted method. The structure, morphology, magnetic and optical properties of the fabricated nanocomposites were systematically characterized. The synthesized nanocomposites were highly efficient to activate peroxymonosulfate (PMS) and hydrogen peroxide (H2O2) as oxidizing agents for degradation of model pharmaceutical pollutants i.e. levofloxacin, tetracycline, ciprofloxacin and doxorubicin. As compared to H2O2, PMS as oxidant exhibits astonishing results for removal of pollutants. The degradation of tetracycline by employing CS@20 %g-CN (0.25 g/L) nanocomposite as catalyst and PMS (2.2 mM) as oxidant was observed in less than 3 min. Among all, CS@20 %g-CN nanocomposite exhibits highest catalytic activity ascribed to synergistic effect of tunable band structure, high surface area and improved separation of charge carriers across the heterojunction. The newly designed nanocomposites can be recycled up to four catalytic cycles and thus offers a promising strategy in meeting future environmental claims for the removal of refractory compounds from wastewater.

Exploration through Structural, Electrical, and Magnetic Properties of Al3+ Doped Ni-Zn-Co Nanospinel Ferrites.

The exploration of aluminum (Al3+) ion substituted nickel–zinc–cobalt (Ni–Zn–Co) nanoferrites is still at the infancy stage, although the structural, electrical, and magnetic properties have been widely investigated. Single-phase cubic nanospinel ferrites of Ni0.4Zn0.35Co0.25Fe2–xAlxO4 (0 ≤ x ≤ 0.12) with space group Fd3m were confirmed by the Rietveld refinement X-ray diffraction (XRD) data. Lattice constants displayed a declining trend with compositions x. The average particle size was found to range from 29 to 25 nm. Selected area electron diffraction (SAED) patterns were indexed according to space group Fd3m, indicating that nanoparticles are well crystallized. Samples’ modes of vibrations swung between redshift and blueshifts as detected in the Raman spectra. The saturation magnetizations (Ms) were in the range of 59.85–86.39 emu/g. Frequency-dependent dielectric constants (ε′) and ac resistivity (ρ) measurement suggested that samples were highly resistive. These resistive nanoferrites with high saturation magnetizations may function effectively for multifaceted electronic devices.

Nanoscale-driven single-domain structure in nickel substituted superparamagnetic cobalt ferrites

In this letter, we reported nickel substituted cobalt nano-ferrites of ∼ 5 nm particle size synthesized with forced hydrolysis methods. The magnitude of the anisotropy constant decreases from 6.06×105 to 2.45×104 erg/cm3 due to the Ni2+ doping. Whereas the gradual increment of Ni2+ ions decreases the blocking temperature from ∼182 k to ∼52 K. The single-domain superparamagnetic behaviour observed here above the blocking temperature. This behaviour could help the material be a promising candidate in quantum technologies as a bit for storage devices.

Efficient degradation of 4-chlorophenol over zirconium, nitrogen and sulphur doped cobalt nanoferrite catalysts

Cobalt ferrite and zirconium doped cobalt ferrite were prepared by coprecipitation method. Nirogen and sulphur ions were doped to it by wet impregnation and co precipitation techniques. The efficiency of the samples towards catalytic wet peroxide oxidation of 4-chlorophenol was checked. Doping increased the catalytic efficacy of cobalt ferrites towards the reaction; zirconium being the most efficient dopant. Complete conversion of 4-chlorophenol with appreciable reduction in chemical oxygen demand(COD) was noted at 50 °C with pollutant to hydrogen peroxide ratio of 1:15. Surface area and nature of the catalyst active surface played deciding role in the oxidation rreaction. The mechanism followed a heterogenous free radical catalysed path as evidenced from metal leaching and radical scavenging studies. The catalysts were magnetically recoverable and stable on repeated uses.

Effect of strontium substitution in cobalt ferrite: Structural and optical studies

A set of strontium (Sr)-doped cobalt (Co) nanoferrites Co1-xSrxFe2O4 (x = 0.1 and 0.2) was synthesized using a sol-gel combustion method. The phase, nanocrystallinity, and optical properties of as-prepared and annealed samples were investigated. The average crystallite sizes obtained were 36, 40, and 30 nm for the nanoferrites with lattice parameters of 8.25, 8.30, and 8.30 Å, respectively. Raman spectroscopy confirmed the spinel structure of the ferrite crystals. The existence of cations at the octahedral and tetrahedral sites in the nanoparticles was also confirmed by X-ray photoelectron spectroscopy. Direct bandgap energy values of 1.29, 1.32, and 1.35 eV were determined and an applied temperature of 680 °C ensured the complete decomposition of precursors. The correlation between the Sr substitution in Co ferrite and the structural and optical changes is discussed.

Low temperature rapid sol–gel auto-combustion synthesis and structural, morphological and magnetic study of nickel substituted cobalt nano ferrites

ABSTRACT The nickel substituted cobalt ferrite nanoparticles were synthesized via the sol–gel auto-combustion method. The single cubic spinel structure formation was confirmed from X-ray diffraction and Fourier transforms infrared spectroscopy study. The effect of lattice strain on crystalline size was studied using Williamson–Hall and the size-strain plot method. A microstructural study was performed using high-resolution field emission scanning electron microscopy. The magnetic properties were studied at room temperature using a vibrating sample magnetometer. The saturation magnetization obtained for pure cobalt nano ferrite was 79.66 emu/g comparable with the value for the bulk sample. The anisotropic constant and anisotropy field were found to be erg/cm3 and 88.66 kOe respectively for pure cobalt ferrite. The high value of saturation magnetization, anisotropic constant and anisotropy field of cobalt ferrite are important parameters for the application of prepared samples in data recording devices.

Effect of Cu Substitution on Magnetic Properties of Co0.6Ni0.4Fe2O4 Nanoferrites

This work is focusing on synthesizing the cobalt nanoferrite materials substituted by copper forming Co0.6Ni0.4-xCuxFe2O4 with x = 0.0, 0.1, and 0.3 using the sol-gel auto-combustion method. The phase analysis of XRD showed the spinel structure with the lattice parameter in the range 8.36-8.39 Å. FESEM image showed the grain size initially decreasing and then increasing with Cu concentration. The FTIR curve's two absorption bands in the specified range of frequency assured the spinel nano ferrite structure. The values of remanent ratios obtained from VSM showed their isotropic nature forming single domain ferrimagnetic particles.

A new method for the preparation of cobalt nanoferrite/graphene composite

The current work reports the preparation of graphene and cobalt nanoferrite /graphene composite by using Plasma Enhanced Chemical Vapor Deposition (PECVD). At first, the cobalt ferrite nanoparticles have been prepared via co-precipitation method. Then the graphene has been deposited by PECVD on one pure Cu substrate and on another Cu substrate coated by the slurry of Co nanoferrite. Raman spectroscopy has been used to ensure the formation of graphene in both graphene and composite samples. The Raman spectrum has also confirmed the existence of the ferrite in the composite. The scanning electron microscope images have revealed a quite uniform porous surface structure of graphene in both samples but the homogeneity has been enhanced in the composite. Moreover, the existence of ferrite slurry layer underneath the graphene has reduced surface defects too. This new successful method of preparing cobalt nanoferrite /graphene composite on a Cu substrate with the aid of PECVD may find a very useful application in producing high performance electrodes in batteries or supercapacitors. Therefore, measuring the electrochemical performance of this prepared composite as an electrode will be our near future work.

Effect of annealing temperature on structural and magnetic properties of nano-cobalt ferrite

Effect of annealing temperature on structural and magnetic properties of nano-cobalt ferrite