Mossbauer Spectroscopy Research Articles

Исследования магнитных наночастиц Mn-=SUB=-x-=/SUB=-Fe-=SUB=-3-x-=/SUB=-O-=SUB=-4-=/SUB=-@OA (0≤ x≤ 1.0) функционализированных олеиновой кислотой (ОА) для биомедицинских применений

Functionalization (or coverage) MNF is a unique tool for creating particles with the properties required for biomedical applications. Therefore, the study of the magnetic properties of coated MNCs is the most important task of our time. The effect of changes in the concentration of Mn ions on the properties of MnxFe3-xO4 nanoparticles coated with oleic acid (OA) MnxFe3-xO4@OA (where x = 0, 0.25, 0.5, 0.75 and 1.0) to create stabilized magnetic fluids for various applications is investigated. The synthesis of MnxFe3-xO4@OA MNPs was carried out by thermal decomposition using manganese-oleate and iron oleate. The properties and phase states of the obtained MNPs were studied by X-ray diffraction (XRD) and Mossbauer spectroscopy. To understand the behavior of MNCs in small magnetic fields during hyperthermic treatment, Mossbauer studies of MnxFe3-xO4@OA particles were carried out when a magnetic field with a strength of 1.7 kOe was applied. It is established that the thermal decomposition method makes it possible to obtain single-phase superparamagnetic particles promising for biomedical applications

Heating of magnetic powders in the ferromagnetic resonance mode at a frequency of 8.9 GHz

Nickel ferrite nanoparticles 4 nm in size were synthesized by chemical deposition. Subsequent annealing at T=700oC for 5 h led to an increase in the particle size to 63 nm. The Mossbauer spectra and the frequency-field dependences of ferromagnetic resonance have been measured. It has been shown that freshly prepared powders are superparamagnetic at room temperature. The kinetic dependences of the heating of nanoparticles in the ferromagnetic resonance mode at a frequency of 8.9 GHz were measured. It was found that the maximum rate of temperature increase in this mode for a ferromagnetic powder is an order of magnitude greater than for the superparamagnetic state (1.2 and 0.13 K/s, respectively). The latter is determined by the saturation magnetization of the studied powders. Keywords: ferromagnetic resonance, superparamagnetic powders, relaxation frequency, frequency-field dependence, heating of powders.

Магнитная структура наночастиц Co-=SUB=-0.8-x-=/SUB=-Mn-=SUB=-x-=/SUB=-Zn-=SUB=-0.2-=/SUB=-Fe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- (x=0.6, 0.4 и 0.2) перспективных для биомедицинских применений

Magnetic nanoparticles (NP) of ferrite Co0.8-xMnxZn0.2Fe2O4 (x=0.6, 0.4 and 0.2) were synthesized by co-deposition. The structural, microstructural, magnetic and ultrathin properties of the obtained particles were investigated by X-ray diffraction and Mössbauer spectroscopy. The nanoparticle sizes calculated from radiographs at x=0.6, 0.4 and 0.2 are 15.2, 10.2 and 10.3 nm, respectively. The influence of the amount of Mn ions introduced on the properties of synthesized particles has been studied. The analysis of experimental Mossbauer spectra showed that the small size of the LF leads to a significant increase in the effects of dimensionality and the influence of the surface on the magnetic structure of the surface layer. The Mossbauer studies, for the first time without the use of external magnetic fields, on the example of MNCH spinel ferrites Co0.8-xMnxZn0.2Fe2O4, found that inside the particle the magnetic moments are ordered collinearly, whereas in the surface layer the moments are oriented at an angle to each other (beveled structure).

Влияние замещения ионами Bi-=SUP=-3+-=/SUP=- на структурно-фазовое состояние и особенности магнитной структуры твердого раствора BaFe-=SUB=-12-x-=/SUB=-Bi-=SUB=-x-=/SUB=-O-=SUB=-19-=/SUB=-

The results of studies of the features of the phase composition, crystal and magnetic structure of Bi-substituted barium hexaferrite BaFe12-xBixO19 (0.1≤ x≤ 1.2) by methods of Mossbauer spectroscopy, X-ray phase analysis, as well as image analysis by scanning electron microscopy are presented. Samples of Bi-substituted hexaferrites - BaFe12-xBixO19 (where x=0.1; 0.3; 0.6; 0.9 and 1.2) were synthesized by the method of solid-phase reactions with double annealing (at T=1100oC for 6 h) and intermediate grinding (for 0.5 h). The X-ray phase analysis allowed us to establish the limit of substitution of Fe3+ ions by Bi3+ ions. It has been shown that at a low level of substitution (x≤0.3) there are no impurity phases detected and the samples are characterized by a single-phase state with the spatial group P63/mmc. When the degree of substitution increases (x>0.3) the formation of impurity phases is noted, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis, as well as the formation of defects in the structure of magentoplumbite due to the large ionic radius of Bi3+. As impurity phases in the studied compositions (x>0.3) Marked: BiFeO3 (Pr. Gr. Pnma); BiO2 (Pr. Gr. Fm-3m); BaBi2O6 (Pr. Gr. R-3) and BaO0,5Bi1,5O2,16 (Pr. Gr. Im-3m). The content of the main phase (Pr. Gr. P63mmc) at the same time decreases from 95.11 to 88.27 vol.% when increasing x from 0.6 to 1.2, respectively. The analysis performed by the method of Messbaurov spectroscopy showed that all Fe ions have a charge of 3+. And all parameters lie within the values characteristic of Fe3+ ions corresponding to the coordination of polyhedra: 12k. 4f2, 2a - octahedra, 4f1 - tetrahedron, and 2b - bipyramide. It is possible to single out a small monotonous decrease only for the 12k position. The analysis of SEM images showed an increase in the average particle size up to 10 mkm, depending on the concentration of bismuth oxide during the synthesis of hexaferrite.

MOSSBAUER AND X-RAY FLUORESCENCE STUDIES OF FLY ASH BASED PROPPANTS

This article discusses the results of the study of proppants obtained from domestic raw materials - bauxite, kaolin and white clay, sand, as well as fly ash by nuclear gamma resonance spectroscopy (the Mossbauer effect) and X-ray fluorescence analysis. The hyperfine structure, electronic states and elemental composition of proppants are given. The results of the study of volatile ash obtained during pulverized coal burning of Ekibastuz, Shubarkul, Karazhyralinsky deposits at thermal power plants are analyzed. According to the results of the studies, various combinations of complex phases and the elemental composition of proppants were determined using Mossbauer spectroscopy and X-ray fluorescence analysis. The Mossbauer measurements were carried out on the MS1104Em spectrometer in the constant acceleration mode with a 57Co source in a chromium matrix at room temperature. The elemental composition of samples of proppants based on fly ash was determined using an energy dispersive X-ray fluorescence spectrometer (RFS) at the EDX-7000 installation of SHIMADZU.

Magnetic studies of dysprosium and indium doped Co2Z hexaferrites

Dysprosium and Indium doped Co2Z hexaferrite Ba3Co2InyDyxFe23.9-xO41 (where x = 0.0, 0.05, 0.1, 0.15, 0.2 and y = 0.1) were fabricated by sol–gel auto-combustion method. The structural studies were done by XRD and TEM which confirms that prepared samples have a pure Z-type phase. The magnetic studies were done by Vibrating Sample Magnetometer and Mossbauer Spectroscopy. The magnetic hysteresis loop of these samples gives us the value of saturation magnetization, coercive field, and remanence magnetization, from these values we found that Ba3Co2In0.1Dy0.2Fe23.7O41 has the highest saturation magnetization value of 89.065 emu/g. Mossbauer spectra fitted with six sextets of six sites least square fitting gives us information about the presence of Fe3+ state in the sample and that there is no deformation in lattice sites by doping with Dysprosium and Indium dopants as magnetic field vary slightly.

Decomposition of fullerite during the high-temperature heating

X-ray diffraction, scanning electron microscopy, Mossbauer and Raman spectroscopy have been used for studying structural changes arising due to the thermal decomposition of fullerite C60/70 at heating to 1600 °C in CO medium. The scheme of the structural changes of fullerite at the initial graphitization temperatures is given. It is shown that the thermal disordering of fullerite with the formation of a fullerite-like amorphous phase is observed at heating above 900 °C. The subsequent ordering of carbon takes place at the temperature of 1600 °C with the formation of a graphite-like amorphous phase. The graphitization process proceeds with the formation of turbostratic carbon and crystalline graphite with a low degree of ordering. The nature of the formation of carbon substructures is considered. Carbon structural changes are accompanied by morphological changes. Comparative studies of changes in the structure of soot, graphite and glass-like carbon during heating have been presented. The catalytic effect of Fe on the processes of the disordering of initial fullerite is considered. It is shown that in the Fe presence the temperature of the phase transition ‘fullerite-graphite’ decreases from 1600 to 760 °C. Graphite, formed after the Fe3C decomposition, is characterized by a higher degree of ordering.

Optimization and characterization of the ternary blended iron rich natural binder concrete system

Around the world, the infrastructure developmental activities searching for new generation cementing binders. Geopolymer is a hard stratum of non-crystalline inorganic alumino-silicate networks developed by alkali activated industrial by-product materials like fly ash, metakaolin and ground granulated blast furnace slag. Laterite is a natural iron-rich aluminosilicate binder material that could be used as a binder with an essential chemical composition. In this research, optimization of iron rich binder content is used to enhance the compressive strength of concrete. For this, various factors were considered and employed in the Taguchi’s experimental technique. An orthogonal array of L16 (4)5 of four parameter levels and four factors are considered to optimize the iron-rich natural material with metakaolin and GGBFS as ternary blend, the molarity of NaOH solution, Na2SiO3to NaOH ratio, and liquid by binder ratio. The results trials showed strength fluctuating between 16 and 60 N/mm2 and the optimized mix obtained as 65 N/mm2. The optimized samples were undergone material characterization to ensure the transformation of iron source activated compound combinations, and the phase changes using FTIR, XRD, SEM-EDS, DTA, Electron paramagnetic resonance spectroscopy, and Mossbauer Spectroscopy.

Role of Ni doping in magnetic dilution of Fe sublattice and in tailoring optical properties of CoFe2O4

The magnetic measurements of the prepared samples of CoFe2-xNixO4 were investigated by SQUID-VSM. We observed a decrease in the coercive field on increasing the doping content, attributed to lower magneto-crystalline anisotropy of dopant Ni2+ than that of the host Fe3+. Also, the merging of FC-ZFC curves approximately at 300 K for all the three samples predicts that the samples are ferrimagnetic up to 300 K. Two sextets can be seen in the Mossbauer spectroscopy, which also indicates that the samples are ferrimagnetic in nature. The bandgap energy calculated from Tauc-plots for pristine and doped samples was found to vary between 2.16 and 2.30 eV. The present bandgap values show the semiconducting behavior of pristine and Ni-doped cobalt spinel ferrite. Therefore, a variety of semiconductor device applications can make use of this material.

Investigation of the sodium storage mechanism of iron fluoride hydrate cathodes using X-ray absorption spectroscopy and mossbauer spectroscopy

Elucidation of a reaction mechanism is the most critical aspect for designing electrodes for high-performance secondary batteries. Herein, we investigate the sodium insertion/extraction into an iron fluoride hydrate (FeF3⋅0.5H2O) electrode for sodium-ion batteries (SIBs). The electrode material is prepared by employing an ionic liquid 1-butyl-3-methylimidazolium-tetrafluoroborate, which serves as a reaction medium and precursor for F− ions. The crystal structure of FeF3⋅0.5H2O is observed as pyrochlore type with large open 3-D tunnels and a unit cell volume of 1129 Å3. The morphology of FeF3⋅0.5H2O is spherical shape with a mesoporous structure. The microstructure analysis reveals primary particle size of around 10 nm. The FeF3⋅0.5H2O cathode exhibits stable discharge capacities of 158, 210, and 284 mA h g−1 in three different potential ranges of 1.5–4.5, 1.2–4.5, and 1.0–4.5 V, respectively at 0.05 C rate. The specific capacities remained stable in over 50 cycles in all three potential ranges, while the rate capability was best in the potential range of 1.5–4.5 V. The electrochemical sodium storage mechanism is studied using X-ray absorption spectroscopy, indicating higher conversion at a more discharged state. Ex-situ Mössbauer spectroscopy strengthens the results for reversible reduction/oxidation of Fe. These results will be favorable to establish high-performance cathode materials with selective voltage window for SIBs.

Mössbauer-based molecular-level decomposition of the Saccharomyces cerevisiae ironome, and preliminary characterization of isolated nuclei.

One hundred proteins in Saccharomyces cerevisiae are known to contain iron. These proteins are found mainly in mitochondria, cytosol, nuclei, endoplasmic reticula, and vacuoles. Cells also contain non-proteinaceous low-molecular-mass labile iron pools (LFePs). How each molecular iron species interacts on the cellular or systems' level is underdeveloped as doing so would require considering the entire iron content of the cell-the ironome. In this paper, Mössbauer (MB) spectroscopy was used to probe the ironome of yeast. MB spectra of whole cells and isolated organelles were predicted by summing the spectral contribution of each iron-containing species in the cell. Simulations required input from published proteomics and microscopy data, as well as from previous spectroscopic and redox characterization of individual iron-containing proteins. Composite simulations were compared to experimentally determined spectra. Simulated MB spectra of non-proteinaceous iron pools in the cell were assumed to account for major differences between simulated and experimental spectra of whole cells and isolated mitochondria and vacuoles. Nuclei were predicted to contain ∼30μM iron, mostly in the form of [Fe4S4] clusters. This was experimentally confirmed by isolating nuclei from 57Fe-enriched cells and obtaining the first MB spectra of the organelle. This study provides the first semi-quantitative estimate of all concentrations of iron-containing proteins and non-proteinaceous species in yeast, as well as a novel approach to spectroscopically characterizing LFePs.

Elucidating Activity-Stability Trade-Off to Design Highly Durable Fe-N-C Catalysts

In this work, we developed a Fe2O3@ZIF-8 composite precursors and combined with a novel thermal activation treatment under an Ar/H2 mixture atmosphere (i.e., forming gas), which successfully prepares a highly active Fe-N-C catalyst. 57Fe Mossbauer spectroscopy analysis experimentally verified that the catalyst only contains S1 sites. The highly active Fe-N-C catalyst achieved exceptional ORR initial activity in acids, exceeding that of a Pt/C baseline catalyst (60 µgPt cm−2) in rotating disk electrode (RDE) tests. The MEA tests further verified that the Fe-N-C catalyst's activity is competitive with Pt/C cathode (0.1 mgPt cm−2) in the kinetic range. Notably, the catalyst demonstrated remarkable activity of 50.8 mA cm−2 (@0.9 ViR-free) under H2-O2 conditions, exceed the U.S. DOE target. As expected, the catalyst degraded significantly during the stability ASTs.To increase S1 sites and address the stability issues, we further developed in-situ CVD methods to treat Fe2O3@ZIF-8 precursors under forming gas flow but with additional N/C precursors that was put at the upstream sides of the tube furnace. Therefore, additional nitrogen and carbon sources are added to the Fe2O3@ZIF-8 precursors during the thermal activation of catalysts. As a results, we can populate the intrinsically stable S2 sites to design highly durable Fe-N-C catalyst. The resulting catalyst presented outstanding stability in both RDE and fuel cell tests. The E 1/2 gained 21 mV after 100,000 cycles of accelerated degradation test (ADT), achieving 0.869 VRHE at the end of the test, which is close to Pt/C (60 µgPt cm−2) in acid electrolyte. The current density of MEA at 0.8 V retained unchanged, and the peak power density increased from 454.0 to 512.0 mW cm−2 in H2-fuel cell after 30,000 cycles of AST.

Quantitative Calculation of the Clustering Behavior of Fe‐Rich and Cr‐Rich REFepCr1−pO3 Crystals

This work has focused on the cluster state of B‐site ions in the rare‐earth perovskite REFepCr1−pO3, and GdFe0.5Cr0.5O3 is taken for instance. This analysis indicates a paramagnetic behavior of the system, which originates from the paramagnetic contribution of the Gd3+. An internal‐field model is used to simplify the superexchange interaction between the A/B‐sites. Furthermore, the cluster state of B‐site ions is computed using the average number of nearest‐neighborhoods. Using Marine Predator Algorithm to fit the experiment data, it is found that Fe–Cr interaction does not conform to the case of ferromagnetic superexchange; therefore, there is no spin glass behavior in this system. Via fitting the Mossbauer spectrum at low temperatures (120 and 12 K), the calculations described above are verified. The calculation gives the hyperfine‐field intervals of 2.47 and 0.92 T at 120 and 12 K. It is found that B‐site ions tend to form clusters. The arrangement of the ions is random and without the tendency of orderly interval occupation of ions (like double perovskite). The study sheds light on the mechanism of single‐ion clustering and introduces new methods for calculating single‐ion clustering states. It can also be applied to the case of other A‐site ions in perovskite system and is not just limited to p = 0.5 in REBpB’1−pO3.

Ecotoxicological assessment of magnetite and magnetite/Ag nanoparticles on terrestrial and aquatic biota from different trophic levels

The aim of the study is an ecotoxicological assessment of magnetite iron oxide-based nanoparticles (NPs), which have risen in popularity in the last decade, on selected terrestrial and aquatic organisms from various levels of the food chain.In the presented study various organisms, from both the terrestrial and aquatic environment, were used as targets for the assessment of NPs ecotoxicity. Plants (radish, oat), marine bacteria (A. fischeri) and crustacean (H. incongruens) were used to represent producers, decomposers, and consumers, respectively. It was found that examined NPs were harmful (to a different degree) to biota from three different trophic levels.Physicochemical characterization (size/morphology, crystallinity, composition, and magnetic properties) of the tested nanoparticles was performed by: transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Mossbauer spectroscopy, respectively.Phytotoxicity was evaluated according to the OECD 208 Guideline, while acute and chronic toxicity of NPs was conducted using bioassays employing bacteria and crustacea, respectively. The phytotoxicity of all investigated iron oxide-based NPs was dependent on concentration and type of NPs formulation and was measured via biomass, seed germination, root length, shoot height, and content of plant pigments.Increasing the concentration of NPs increased phytotoxicity and mortality of aquatic organisms. Ecotoxicity of iron oxide/silver was dependent on the size and content of silver. Iron oxide NPs coated with nanosilver in a percentage ratio of 69/31 were found to be the most toxic on tested terrestrial and aquatic biota.

Crystal Structure Dynamics of RFe3(BO3)4 Single Crystals in the Temperature Range 25–500 K

The multiferroic RFe3(BO3)4 family is characterized by diverse magnetic, magnetoelectric, and magnetoelastic properties, the fundamental aspects of which are essential for modern electronics. The present research, using single-crystal X-ray diffraction (XRD) and Mössbauer spectroscopy (MS) in the temperature range of 25–500 K, aimed to analyze the influence of local atomic coordination on magnetoelectric properties and exchange and super-exchange interactions in RFe3(BO3)4. Low-temperature, single-crystal XRD data of the magnetically ordered phase of RFe3(BO3)4 at 25 K, which were obtained for the first time, were supplemented with data obtained at higher temperatures, making it possible to draw conclusions about the mechanism of the structural dynamics. It was shown that, in structures with R = Gd, Ho, and Y (low-temperature space group P3121), a shift in oxygen atoms (O2, second coordination sphere of R atoms) was accompanied by rotation of the B2O3 triangle toward R atoms at low temperatures, and by different rearrangements in iron chains of two types, in contrast to Nd and Sm iron borates (space group R32). These rearrangements in the structures of space group P3121 affected the exchange and super-exchange paths at low temperatures. The MS results confirm the influence of the distant environment of atoms on the magnetoelectric properties of rare-earth iron borates at low temperatures.

Disappearance of spiral spin order and field induced spin reorientation transition in Fe[formula omitted]Cr[formula omitted]VO[formula omitted] (0.1[formula omitted][formula omitted][formula omitted]0.3) multiferroic: 57Fe Mössbauer spectroscopic studies

Here we report a progressive suppression of spiral spin order and evidence for disappearance of spin reorientation transition (SRT) in Fe1−xCrxVO4 (0.1 ≤x≤ 0.3) studied by low temperature and high magnetic field (LTHM) Mössbauer spectroscopy (MS). Variation in the area ratio of lines 2 and 3 (A23) with external magnetic field confirms the presence of antiferromagnetic (AFM) ordering for all the compositions at the lowest temperatures (5 K). Field induced spin reorientation transition is being observed in both triclinic (x = 0.10) and mixed phase (x = 0.175) systems, evidenced by the change in the sign of quadrupole shift (QS) value at low temperatures, where as the SRT is absent in the monoclinic phase (x = 0.20 and 0.30). MS line width (Γ) values indicate the presence of spiral spin order in T-phase, partial suppression in mixed phase (T + M) and finally complete suppression for the M-phases.

Effects of Potassium Loading over Iron–Silica Interaction, Phase Evolution and Catalytic Behavior of Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

Potassium (K) promoter and its loading contents were shown to have remarkable effects on the Fe–O–Si interaction of precipitated Fe/Cu/K/SiO2 catalysts for low-temperature Fischer-Tropsch synthesis (FTS). With the increase in K content from 2.3% (100 g Fe based) up to 7% in the calcined precursors, Fe–O–Si interaction was weakened, as reflected by ATR/FTIR, H2-TPR and XPS investigations. XRD results confirmed that the diffraction peak intensity from (510) facet of χ-Fe5C2 phase strengthened with increasing K loading, which indicates the crystallite size of χ-Fe5C2 increased with the increase in K contents either during the syngas reduction/carburization procedure or after FTS reaction. H2-TPH results indicated that more reactive surface carbon (alpha-carbon) was obtained over the higher K samples pre-carburized by syngas. Raman spectra illustrated that a greater proportion of graphitic carbon was accumulated over the surface of spent samples with higher K loading. At the same time, ATR-FTIR, XRD and Mössbauer spectra (MES) characterization results showed that a relatively higher level of bulk phase Fayalite (Fe2SiO4) species was observed discernibly in the lowest K loading sample (2.3 K%) in this work. The catalytic evaluation results showed that the CO conversion, CO2 selectivity and O/P (C2–C4) ratio increased progressively with the increasing K loading, whereas a monotonic decline in both CO conversion and O/P (C2–C4) ratio was observed on the highest K loading sample during c.a. 280 h of TOS.

Generating High‐valent Iron‐oxo ≡FeIV=O Complexes in Neutral Microenvironments through Peroxymonosulfate Activation by Zn−Fe Layered Double Hydroxides

AbstractThe universal limit on the pH conditions is disturbing peroxymonosulfate (PMS)‐triggered high‐valent iron‐oxo systems in environmental applications. Here, we propose for the first time the construction of a neutral microenvironment on the surface of Zn−Fe layered double hydroxide (ZnFe‐LDH) by using the amphoteric properties of zinc hydroxide, which continuously generates ≡FeIV=O over a wide pH range of 3.0–11.0 in activating PMS. The ≡Zn(OH)2 moiety offers a neutral microenvironment at the phase interface, which mitigates the self‐decomposition of ≡FeIV=O by protons and the hydrolysis reaction of iron by hydroxyl groups, which is supported by the Mossbauer spectra, density functional theory calculations and designed experiments. Consequently, ZnFe‐LDH/PMS can satisfy the stability in long‐term experiments, selectivity under conditions with high salinity or natural organic matter and efficient treatment of actual wastewater.

Generating High‐valent Iron‐oxo ≡FeIV=O Complexes in Neutral Microenvironments through Peroxymonosulfate Activation by Zn−Fe Layered Double Hydroxides

The universal limit on the pH conditions is disturbing peroxymonosulfate (PMS)-triggered high-valent iron-oxo systems in environmental applications. Here, we propose for the first time the construction of a neutral microenvironment on the surface of Zn-Fe layered double hydroxide (ZnFe-LDH) by using the amphoteric properties of zinc hydroxide, which continuously generates ≡FeIV =O over a wide pH range of 3.0-11.0 in activating PMS. The ≡Zn(OH)2 moiety offers a neutral microenvironment at the phase interface, which mitigates the self-decomposition of ≡FeIV =O by protons and the hydrolysis reaction of iron by hydroxyl groups, which is supported by the Mossbauer spectra, density functional theory calculations and designed experiments. Consequently, ZnFe-LDH/PMS can satisfy the stability in long-term experiments, selectivity under conditions with high salinity or natural organic matter and efficient treatment of actual wastewater.

Analysis of Raman, Mossbauer Spectra and Dielectric Behaviour of Sol-Gel Prepared Ni1-xCoxFe2O4 Spinel Ferrites

Single-phase spinel ferrites with formula of Ni1−xCoxFe2O4 where x values are varying from 0 to 1 with 0.25 steps were synthesized by sol-gel technique. Microstructure, cation distribution, valence state of iron and dielectric properties have been discussed. From the deconvoluted Raman spectra the positions of five Raman modes and intensity variation was calculated. Cationic arrangement in A and B sites was estimated from deconvoluted Raman peaks. The characteristic magnetic patterns of ferrites were given by room temperature Mossbauer spectra. Parameters like isomer shift, hyperfine magnetic field, quadrupole shift were estimated for all ferrites after fitting Mossbauer spectra. From XPS (X-ray Photoelectron Spectroscopy) analysis +3 ionic state for iron was found. Dielectric parameters were also studied for ferrites at room temperature. NiFe2O4 and Ni0.75Co0.25Fe2O4 had high values of dielectric permittivity, AC conductivity and loss tangent. The ferrite Ni0.5Co0.5Fe2O4 showed very less dielectric constant and conductivity values and dielectric loss resonance peak was around 1 kHz.