A review on MnZn ferrites: Synthesis,characterization and applications

Researchers are taking great interest in the synthesis and characterization of MnZn ferrites due to their wide range of applications in many areas. MnZn ferrites are a class of soft magnetic materials that have very good electrical, magnetic and optical properties. The properties of MnZn ferrites include high value of resistivity, permeability, permittivity, saturation magnetization, low power losses and coercivity. The above mentioned advantageous features of MnZn ferrites make them suitable for the use in various applications. In biomedical field these ferrites are used for cancer treatment and MRI. MnZn ferrites are also used in electronic applications for making transformers, transducers and inductors. These ferrites are also used in magnetic fluids, sensors and biosensors. MnZn ferrite is highly useful material for several electrical and electronic applications. It finds applications in almost every household appliances like mobile charger, LED bulb, TV, refrigerator, juicer mixer, washing machine, iron, microwave oven, mobile, laptop, desktop, printer and so on. Therefore, the present review focuses on different techniques for synthesis of MnZn ferrites in literature, their characterization tools, effect of doping on the properties of MnZn ferrite and finally we will discuss about their applications.     

Synthesis, magnetic and optical properties of core/shell Co1-xZnxFe2O4/SiO2 nanoparticles

The optical properties of multi-functionalized cobalt ferrite (CoFe₂O₄), cobalt zinc ferrite (Co_0.5Zn_0.5Fe₂O₄), and zinc ferrite (ZnFe₂O₄) nanoparticles have been enhanced by coating them with silica shell using a modified Stöber method. The ferrites nanoparticles were prepared by a modified citrate gel technique. These core/shell ferrites nanoparticles have been fired at temperatures: 400°C, 600°C and 800°C, respectively, for 2 h. The composition, phase, and morphology of the prepared core/shell ferrites nanoparticles were determined by X-ray diffraction and transmission electron microscopy, respectively. The diffuse reflectance and magnetic properties of the core/shell ferrites nanoparticles at room temperature were investigated using UV/VIS double-beam spectrophotometer and vibrating sample magnetometer, respectively. It was found that, by increasing the firing temperature from 400°C to 800°C, the average crystallite size of the core/shell ferrites nanoparticles increases. The cobalt ferrite nanoparticles fired at temperature 800°C; show the highest saturation magnetization while the zinc ferrite nanoparticles coated with silica shell shows the highest diffuse reflectance. On the other hand, core/shell zinc ferrite/silica nanoparticles fired at 400°C show a ferromagnetic behavior and high diffuse reflectance when compared with all the uncoated or coated ferrites nanoparticles. These characteristics of core/shell zinc ferrite/silica nanostructures make them promising candidates for magneto-optical nanodevice applications.     

Magnetic CoFe2O4 nanoparticles doped with metal ions: A review

Ceramic-magnetic nanoparticles (CMNPs) are attracting attention due to their various applications, especially in biomedical industries. Among them, spinel ferrite CMNPs have received considerable deliberations among different spinel metal oxides due to their fascinating characteristics. Spinel ferrite CMNPs are used for enhancement of the applicability of CMNPs without affecting the intrinsic advantages of iron oxide CMNPs. Spinel ferrites with doping agents have useful electrical and magnetic properties in various fields. Moreover, the replacement of metallic atoms in ferrites is promising to manipulate physical characteristics and improve their performance. Among different spinel ferrites, CoFe₂O₄ nanoparticles are the most investigated CMNPs. Furthermore, they are used as permanent magnets, magnetic recorders in high-density and micro-wave devices, and magnetic fluids. This study reviews the CoFe₂O₄ nanoparticles doped with various elements and their applications in various fields.     

Electrosynthesis of Co,Ni and Zn ferrites nanoparticles in the presence of external magnetic field

Magnetic complex oxides of iron nanoparticles are among the most important materials that have been studied. They have been widely used in different areas such as electronic devices, information storage, biomedical areas, drug-delivery, catalyst, and wastewater treatment. In different applications of nanoparticles, the shape and size of particles are very important because the electrical, optical, and magnetic properties of the nanoparticles depend on their dimension. In this study, nanoparticles of cobalt, nickel, and zinc ferrites were synthesized in uniform size by an electrochemical technique. First, the anode was made electrochemically by depositing each metal of zinc, nickel, and cobalt on the iron sheet from the solutions of 0.1 M Co²⁺, Ni²⁺, and Zn²⁺ ions as the precursor. Then the electrosynthesis of ferrite nanoparticles was performed in a second electrochemical cell where the prepared electrode was anode and stainless steel (316L) was cathode in the electrolyte solution of CTAB 0.04 M. The optimized value of current density was applied to the electrochemical cell. After then the same synthesis was carried out in the magnetic field supplied by two magnets. The prepared nanoparticles were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The magnetic properties were investigated by vibrating sample magnetometer (VSM). The comparison of two samples prepared in the magnetic field and without it showed the average size of the samples synthesized in the magnetic field was in the narrower size distribution of 20–30 nm and the saturation magnetization of the nanoparticles increased in the magnetic field.     

纳米结构铁氧体磁性材料的制备和应用

铁氧体纳米磁性材料是一类非常重要的无机功能材料,其应用涉及到电子、信息、航天航空、生物医学等领域。综述了纳米结构铁氧体磁性材料化学制备方法的研究进展,分析了相关纳米结构铁氧体磁性材料的制备工艺对磁性能的影响,以及它们的应用,展望了研究和开发纳米结构铁氧体磁性材料的新性能和新技术的应用前景。     

His-tagged protein immobilization on cationic ferrite magnetic nanoparticles

Magnetic nanoparticles have been applied in various fields because of their interesting magnetic properties. Immobilization on magnetic nanoparticles is a very important step in functionalizing them. We examined protein immobilization efficiency using interactions between his-tagged enhanced green fluorescence protein and affordable cationic ferrite magnetic nanoparticles for the first time. Four types of ferrite magnetic nanoparticles were verified: cobalt iron oxide, copper iron oxide, nickel iron oxide, and iron (III) oxide as negative controls. Among the four ferrite magnetic nanoparticles, copper ferrite magnetic nanoparticle was confirmed to have the highest immobilization efficiency at 3.0 mg proteins per gram ferrite magnetic nanoparticle and 78% of total enhanced green fluorescence protein. In addition, the maximum binding efficiency was determined for copper ferrite magnetic nanoparticle. Consequently, this newly verified his-tag-immobilizing capacity of copper ferrite magnetic nanoparticle could provide a facile, capable, and promising strategy for immobilizing his-tagged proteins or peptides with high purity for biosensors, magnetic separation, or diagnostics.     

Erbium substituted nickel–cobalt spinel ferrite nanoparticles: Tailoring the structural,magnetic and electrical parameters

In this article, we have reported an effective, rapid as well as economical Er³⁺ substituted Ni_0.4Co_0.6Fe₂O₄ ferrite nanoparticles synthesized via surfactant-assisted co-precipitation route. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), dielectric properties, current-voltage (I–V) measurements, and vibrating sample magnetometry (VSM). XRD and FTIR confirmed the face-centered (FCC) spinel structure of all compositions of the synthesized spinel ferrite nanoparticles. The deviations in the lattice constant granted with the variation in size of the guest (Er³⁺) and host (Fe³⁺) cations. These ferrites were also subjected for electrical, magnetic and dielectric investigations. I–V measurements showed that resistivity values decreased from 6.20 × 10⁷ Ω cm to 0.03 × 10⁷ Ω cm with the increased Er³⁺ contents. Saturation magnetization increased from 35.99 to 39.95 emu/g. This high value of saturation magnetization suggested the possible utilization of such ferrites for practical applications such as microwave and recording devices fabrication. Interestingly, the magnetic and dielectric properties of nickel-cobalt ferrite nanoparticles showed ample improvement upon Er³⁺ substitution. The results clearly indicate the potential of Er⁺³ substituted spinel ferrite particles in various advanced technological devices fabrication.     

Investigation of structural,optical and magnetic properties of thermal plasma synthesized Ni-Co spinel ferrite nanoparticles

Magnetic nanoparticles of nickel substituted cobalt ferrites, Ni_xCo_1−xFe₂O₄, (x=0 to 1 in the step of 0.2) were successfully synthesized by gas phase nucleation and growth process. For the first time, we report feasibility of synthesizing such mixed ferrite system using thermal plasma route. Further, effect of change in molar ratio of Co:Ni on the structural, optical and magnetic properties has been investigated in detail. The structural and phase formation analysis of the samples under investigation have been carried out using powder X-ray diffraction and Raman spectroscopy. The surface morphology of these particles has been studied using scanning electron microscopy and the micrographs so obtained were used to find out average gain size and size distribution. The optical and magnetic properties of the as synthesized samples were finally correlated with the magnetic moment of substituted species such as Ni for Co and cation distribution, analyzed using Mössbauer spectroscopy. Special modification in Thermo Gravimetric Analyzer was used to determine magnetic transition temperature.     

Effect of Synthesis Parameters on the Magnetic Properties of Manganese Zinc Ferrites

The magnetic properties which make high permeability manganese zinc ferrites useful in telecommunications applications are strongly affected by both the composition and the synthesis method. Some of the effects discussed are: (a) variation of the magnitude and temperature dependence of the permeability as a function of the composition, (b) effect of the type of ferric oxide used in the synthesis on these two magnetic parameters, (c) effect of the sintering atmosphere on the disaccommodation and the temperature dependence of the permeability, and (d) the relation between the ferrous ion concentration and the disaccommodation characteristics of the ferrite materials.     

Combustion and Coprecipitation Synthesis of Co–Zn Ferrite Nanoparticles: Comparison of Structure and Magnetic Properties

In this study, we used urea and ammonia to synthesize zinc cobalt ferrites via microwave‐assisted hydrothermal method from metallic nitrates. It was figured that despite the common synthesis method and equal amount of nitrates, magnetic properties of nanoparticles were different. Changes in magnetic properties are discussed based on factors such as nanoparticles’ size, surface atom spins, cationic distribution, magnetocrystalline energy. Nanoparticles synthesized with ammonia showed lower magnetization while higher magnetocrystalline energy and greater coercivity was obtained due to better cationic distribution. It was also revealed that by increasing magnetization, the susceptibility of nanoparticles increases and then declines.     

Controlling transport and chemical functionality of magnetic nanoparticles

A wide range of metal, magnetic, semiconductor, and polymer nanoparticles with tunable sizes and properties can be synthesized by wet-chemical techniques. Magnetic nanoparticles are particularly attractive because their inherent superparamagnetic properties make them desirable for medical imaging, magnetic field assisted transport, and separations and analyses. With such applications on the horizon, synthetic routes for quickly and reliably rendering magnetic nanoparticle surfaces chemically functional have become an increasingly important focus. This Account describes common synthetic routes for making and functionalizing magnetic nanoparticles and discusses initial applications in magnetic field induced separations. The most widely studied magnetic nanoparticles are iron oxide (Fe2O3 and Fe3O4), cobalt ferrite (CoFe 2O4), iron platinum (FePt), and manganese ferrite (MnFe 2O4), although others have been investigated. Magnetic nanoparticles are typically prepared under either high-temperature organic phase or aqueous conditions, producing particles with surfaces that are stabilized by attached surfactants or associated ions. Although it requires more specialized glassware, high-temperature routes are generally preferred when a high degree of stability and low particle size dispersity is desired. Particles can be further modified with a secondary metal or polymer to create core-shell structures. The outer shells function as protective layers for the inner metal cores and alter the surface chemistry to enable postsynthetic modification of the surfactant chemistry. Efforts by our group as well as others have centered on pathways to yield nanoparticles with surfaces that are both easily functionalized and tunable in terms of the number and variety of attached species. Ligand place-exchange reactions have been shown quite successful for exchanging silanes, acids, thiols, and dopamine ligands onto the surfaces of some magnetic particles. Poly(ethylene oxide)-modified phospholipids can be inserted into nonpolar surface monolayers of as-prepared nanoparticles as a method for modifying the surface chemistry that induces water solubility. In general, reactive termini can subsequently be used to append a range of chemical groups. For example, surfactants with trifluoroethylester or azide termini have been used to attach a range of amine- or alkyne-containing species, respectively. Chemically functionalized magnetic nanoparticles are promising as advanced materials for analytical separations and analysis. Magnetic field flow fractionation leverages the size-dependent magnetic moments to purify and separate the components of a complex mixture of particles. Similarly, magnetic field gradients are useful for manipulating transport and separation in simple microfluidic devices. By either approach, magnet-induced transport of the particles is a simple method in which an attached reagent, catalyst, or bioanalytical tag can be moved between flow streams within a lab on a chip device.     

Scanning pulsed laser ablation in liquids: An alternative route to obtaining biocompatible YbFe nanoparticles as multiplatform contrast agents for combined MRI and CT imaging

Ytterbium ferrites are being used in many promising applications, such as visible-light photocatalysis, solar cells, magnetooptic devices, electro-magnetic equipment, etc., due to their fantastic ferroelectric and ferromagnetic properties. However, despite their good magnetic and radiopaque features, the use of ytterbium ferrites as multiplatform contrast agents in magnetic resonance imaging (MRI) and X-ray computed tomography (CT) is still under-developed. This is mainly due to difficulties in obtaining stable and biocompatible aqueous colloidal dispersions of ytterbium ferrite nanoparticles. In order to overcome this limitation, this work explores an eco-friendly method to directly synthesize such dispersions by liquid-assisted pulsed laser ablation of ytterbium ferrite massive targets. First, orthorhombic bulk YbFeO₃ targets were obtained by a reaction-sintering method. Then, colloidal dispersions of nanoparticles were produced directly in both distilled water and ethanol by irradiating the bulk YbFeO₃ targets with high-power infrared nanosecond lasers pulses. A battery of techniques has been used to characterize the as synthesized YbFeO₃ targets and colloidal dispersions of YbFe nanoparticles to determine their composition, structure, magnetic properties, X-ray attenuation potentials, and colloidal properties. Moreover, the biocompatibility of the systems was also analysed by MTT cell viability assay. Results indicated that the use of distilled water as ablation medium yields colloidal dispersions consisted mainly of paramagnetic ytterbium ferrite nanoparticles. Contrarily, the use of ethanol as solvent leads to colloidal dispersions of polycrystalline nanoparticles with both ferromagnetic and paramagnetic behaviour, due to the coexistence, in each nanoparticle, of ytterbium ferrite, ytterbium oxide, and iron oxide crystalline phases. Both colloidal dispersions exhibit also high biocompatibility and suitable X-ray attenuation properties. Moreover, they show bio-safe hydrodynamic sizes (lower than 200 nm) with acceptable overall hydrodynamic polydispersity index values (under 0.4), being stable in water for several weeks. These results pave the way for the future evaluation of Yb–Fe based nanoparticles as multiplatform contrast agents in multimodal MRI and CT imaging.     

Anisotropy investigation of cobalt ferrite nanoparticles embedded in polyvinyl alcohol matrix: A Monte Carlo study

The magnetic properties of the cobalt ferrite/polyvinyl alcohol nanocomposites have been studied experimentally and theoretically. For investigation the impact of polymeric matrix on magnetic properties of magnetic nanoparticles, four different processes have been considered for synthesizing the polymer based nanocomposites by co-precipitation method. The effective magnetic anisotropy obtained by Monte Carlo simulation and law of approach to the saturation magnetization showed a significant decrease relative to the bulk and bare cobalt ferrite nanoparticles. The polymeric matrix interacted with the surface of particles by different strength and made them approximately non-interacting. The as synthesized samples characterized by X-Ray diffractions (XRD) and Fourier transform infrared spectroscopy (FT-IR). Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM).     

Copper substituted nickel ferrite nanoparticles anchored onto the graphene sheets as electrode materials for supercapacitors fabrication

Nickel ferrites with high theoretical capacitance value as compared to the other metal oxides have been applied as electrode material for energy storage devices i.e. batteries and supercapacitors. High tendency towards aggregation and less specific surface area make the metal oxides poor candidate for electrochemical applications. Therefore, the improvements in the electrochemical properties of nickel ferrites (NiFe₂O₄) are required. Here, we report the synthesis of graphene nano-sheets decorated with spherical copper substituted nickel ferrite nanoparticles for supercapacitors electrode fabrication. The copper substituted and unsubstituted NiFe₂O₄ nanoparticles were prepared via wet chemical co-precipitation route. Reduced graphene oxide (rGO) was prepared via well-known Hummer's method. After structural characterization of both ferrite (Ni_1-xCu_xFe₂O₄) nanoparticles and rGO, the ferrite particles were decorated onto the graphene sheets to obtain Ni_1-xCu_xFe₂O₄@rGO nanocomposites. The confirmation of preparation of these nanocomposites was confirmed by scanning electron microscopy (SEM). The electrochemical measurements of nanoparticles and their nanocomposites (Ni_0.9Cu_0.1Fe₂O₄@rGO) confirmed that the nanocomposites due to highly conductive nature and relatively high surface area showed better capacitive behavior as compared to bare nanoparticles. This enhanced electrochemical energy storage properties of nanocomposites were attributed to the graphene and also supported by electrical (I-V) measurements. The cyclic stability experiments results showed ~65% capacitance retention after 1000 cycles. However this retention was enhanced from 65% to 75% for the copper substituted nanoparticles (Ni_0.9Cu_0.1Fe₂O₄) and 65–85% for graphene based composites. All this data suggest that these nanoparticles and their composites can be utilized for supercapacitors electrodes fabrication.     

Preparation and magnetic properties of titanium-substituted LiZn ferrites via a sol-gel auto-combustion process

A series of nitrate–citrate gels were prepared from metal nitrates and citric acid via a sol-gel process, in order to synthesize titanium-substituted lithium zinc (LiZn) ferrites with composition of Li_0.5(0.4+x)Zn_0.6Ti_xFe_(2.2−1.5x)O₄ (x ranging from 0.05 to 0.20). The thermal decomposition process was investigated by DTA-TGA, IR and XRD techniques. The dried gels can burn in a self-propagating combustion process in air to transform into single-phase, nano-crystalline ferrite particles. The low-temperature sintering was realized using the synthesized powders, and the sintered ferrites have fine-grained microstructures and excellent magnetic properties. Appropriate amounts of titanium substituted for Fe in LiZn ferrites can significantly increase the permeability value. The prepared LiZn ferrites are good materials for multilayer chip inductors.     

Novel polyvinyl alcohol polymer based nanostructure with ferrites co‐doped with nickel and cobalt ions for magneto‐sensor application

Uniform nanosheet‐like structures were synthesized by the polymer based co‐precipitation route. Different concentrations of polyvinyl alcohol (pure (0 g), 0.2 g and 0.5 g) were added to nickel (Ni) and cobalt (Co) ion co‐doped ferrite magnetic nanoparticles. X‐ray diffraction confirmed a spinel structure phase of the Ni ? Co ferrites. Enhanced average crystallite size (6.7%) of the Ni ? Co ferrites was found on polymer incorporation. The molecular functional group of polyvinyl alcohol and Ni ? Co ferrites was confirmed by infrared and Raman spectroscopy techniques. On adding polymer, the spherical morphology of the Ni ? Co ferrites was tailored to nanosheets (200 nm × 300 nm). Therefore, the polymer based co‐precipitation technique is an inexpensive, simple and effective route to engineer the morphology of the magnetic nanostructure and could be useful for gas sensor and magnetic sensors. © 2016 Society of Chemical Industry     

Augmenting the photocatalytic performance of cobalt ferrite via change in structural and optical properties with the introduction of different rare earth metal ions

In the present study, synthesis of different rare earth (RE) doped cobalt ferrite nanoparticles was done via facile sol-gel auto-combustion method using four different RE metal ions: Eu, Gd, Dy and Nd. The RE substituted cobalt ferrite nanoparticles were then characterized using FT-IR, powder XRD, HR-TEM, SAED, EDX, VSM and DRS techniques. From the characterization results, a significant variation in the structural, magnetic and optical properties of pure cobalt ferrite was observed with the introduction of different RE metal ions. This change in the properties was emerged due to the distortion of the ferrite crystal lattice due to replacement of smaller ionic radii Fe³⁺ ions with the comparatively larger ionic radii RE³⁺ metal ions. The catalytic activity of the fabricated RE doped cobalt ferrite nanoparticles was studied for the photo-Fenton degradation of cationic and anionic dyes. Under visible light irradiation, the as prepared RE doped nanoparticles exhibited great enhancement in the photo-Fenton degradation of dye molecules as compared to pure cobalt ferrite nanoparticles. The enhancement in the degradation rate was ascribed to the generation of defects in the crystal lattice, lower crystallite size and reduced band gap energy values which facilitated the facile transfer of photo-generated holes and electrons. Best catalytic results were obtained for CoNd_0.08Fe_1.92O₄ for SO dye (k?=?2.23?×?10^?1 min^?1) which were found to be around 9 times higher than the pure cobalt ferrite nanoparticles (k?=?0.23?×?10^?1 min^?1).     

Structural and Magnetic Property of Co1‐xNixFe2O4 Nanoparticles Synthesized by Hydrothermal Method

The cobalt nickel ferrite (Co_1‐xNi_xFe₂O₄ x = 0–1.0) nanoparticles were synthesized by a hydrothermal method. Effects of nickel content and organic template on the microstructure and magnetic property of the nanoparticles were studied. The experimental results indicate that Ni²⁺ substitution for Co²⁺ and special synthesis technique leads to obvious change in microstructure and magnetic property of the ferrites. The ferrites show nonlinear variations in the saturation magnetization and the coercivity with nickel substitution, which are explained by shape anisotropy and supernormal cation distribution. The organic template also leads to variation in the microstructure and properties of the nanoparticles.     

The influence of lanthanum concentration on microstructural and electrical properties of Mg-Cd-Bi ferrite nanoparticles

Lanthanum (La³⁺) substituted Mg-Cd-Bi ferrite nanoparticles were synthesized by sol-gel auto combustion route consuming high quality nitrates. The impact of lanthanum concentration on microstructural and electrical properties in the ferrite series Mg_0.5Cd_0.5Fe_1.95Bi_0.5-xLa_xO₄ (x = 0.0, 0.01, 0.02, 0.03, 0.04, 0.05) was investigated. The samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscope (SEM), and Current-voltage (I-V) analyzerfor compositional, structural, morphological and electrical analysis. Upon varying the lanthanum content, it is observed that all the samples retained perovskite BiFeO₃ phase with distorted rhombohederal structure. Furthermore, it is revealed that the sintering process can significantly control the structural defects and crystal imperfections which affect the electric and magnetic nature of ferrites. The conduction process in La³⁺-dopedferrite series is originated by the hopping of electrons between ions of same elementswhich reduced the electrical resistivity and depicts the semiconductor nature of synthesized samples.Thus, it is believed that the optimal doping of lanthanum content in La³⁺-substituted Mg-Cd-Bi ferrites followed by post-annealing can remarkably tune the electrical properties of synthesized ferrite nano particles.     

Structural,morphological, and magnetic properties of ZnxCo1-xFe2O4 (0 ≤ x ≤ 1) prepared using a chemical co-precipitation method

In the present study, the chemical co-precipitation technique was adopted to synthesize Zn_xCo_1-xFe₂O₄ (ZCF) (0?≤ x?≤?1) ferrites. The thermogravimetric-differential thermal analysis results revealed that above 405?°C, the precursor had decomposed and ferrite formation had occurred. The structure and morphology of the prepared ferrite nanoparticles were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy (FE-SEM). The synthesized polycrystalline nanoparticles had a cubic spinel structure and the crystallite size was in the range of 6.09–12.98?nm. The prepared ferrites appeared as nearly spherical nanoparticles with a particle size in between 0.13 and 0.23?µm, as confirmed using FE-SEM. The elemental composition was determined using the energy-dispersive X-ray spectroscopy technique. The influence of the Zn-substituted cobalt ferrites (ZCF) on the structural, morphological, and magnetic properties were studied. The magnetic properties of the ZCF samples such as saturation magnetization, remanence magnetization, and coercivity measured at room temperature were 0.387–2.065?emu/g, 0.057–1.282?emu/g, and 60–1834?Oe, respectively. It was confirmed from the nature of the hysteresis loops that the given ZCF samples can be considered as a soft magnetic material.