Fe2O4 Spinel Research Articles

Cd-doping effect on morphologic, structural, magnetic and electrical properties of Ni0.6-xCdxMg0.4Fe2O4 spinel ferrite (0 ≤ x ≤ 0.4)

The effect of Cd-doping on physical properties of Ni0.6-xCdxMg0.4Fe2O4 spinel ferrite has been investigated. Scanning electron spectroscopy (SEM) confirms the formation of grain and grain boundaries in these samples and the presence of all chemical elements introduced was confirmed by EDS. The X-ray analyses indicate that all the compounds have the cubic structure with Fd3¯m space group, cell parameter increase which Cd content. A ferromagnetic state at room temperature for all compounds is detected by a magnetization measurement of hysteresis loops. We note that the saturation magnetization increases with Cd content, however, the remnant magnetization, and the corrective field decreases. DC electrical conductivity analysis shows a semiconductor behavior for all sample. In addition, non-overlapping small polaron tunneling (NSPT) and the overlapping large polaron tunneling (OLPT) are the dominants conductions mechanisms in our samples.

Critical behavior in Ni0.15Cu0.15 Zn0.7Fe2O4 spinel ferrite

Abstract We report an in-depth investigation of the critical behavior in Ni0.15Cu0.15Zn0.7Fe2O4 (NCZFO) spinel ferrite synthesized via the solid-state reaction method. The structural analysis demonstrates that NCZFO belongs to the Fd 3 ¯ m space group of the cubic crystal system. The magnetic transformation in NCZFO at approximately TC = 290 K is of the second order, as per the Banerjee criteria. Employing various models, we have attempted to estimate the CP (critical parameter) values. The self-consistency of the CPs is confirmed by Widom's relation as well as the scaling hypothesis. The values of the CPs manifest that the magnetic ordering in NCZFO belongs to the Heisenberg theory in three dimensions, signifying short-range ferromagnetic interactions. The relationship between the exchange distance (J(r)) and the spatial distance (r) in NCZFO are expected to decline as J(r) ∼r−4.947.

Study of Alternating Magnetic Heating Characteristics of MnZn Ferrite Nanoparticles for Magnetic Hyperthermia Applications

In this study, we report the synthesis of Mn0.5Zn0.5Fe2O4 spinel ferrites by solvothermal method based on ethylene glycol for magnetic hyperthermia applications. X-ray diffraction analysis of as synthesized spinel ferrites confirm the cubic spinel structure having crystallite sizes in the range between 17 to 22 nm. The particles morphology was investigated by scanning electron micrographs, and the results indicate that all particles are in regular spherical shape with narrow particle size distribution. Magnetic properties were measured by using a vibrating sample magnetometer at room temperature. The heating effect of as synthesized spinel ferrites were studied under alternating current magnetic field (36 KA m−1 and 286 kHz). In particular, the sample synthesized in EG: H2O = 2:1 solvent system shows the highest specific absorption rate of 224.84 W/g at the concentration of 5 mg/mL.

Modulation of magnetism and study of impedance and alternating current conductivity of Zn0.4Ni0.6Fe2O4 spinel ferrite

A spinel ferrite sample Zn0.4Ni0.6Fe2O4 was prepared by a conventional solid-state reaction method at high temperature. This compound was found to exhibit a single phase and crystallize in a cubic structure with Pm3 m Space group. The complex impedance was investigated in the temperature range 400–700 K and in the frequency range 100 Hz - 1 MHz. The Z-impedance analysis revealed that the relaxation phenomenon is strongly dependent on temperature and frequency. The impedance plane plot showed semi-circle arcs at different temperatures, and a proposed electrical equivalent circuit explained its results. The temperature and frequency dependence of the ac conductivity was shown to obey the universal Jonscher's power law. The activation energy, inferred from the impedance spectrum, was confirmed to match very well with those estimated from the conduction mechanism, indicating that the relaxation process and conductivity have the same origin. The magnetization is due to the ferromagnetic interactions between iron ions.

Corrosion mechanisms of magnesia-chrome refractories in copper slag and concurrent formation of hexavalent chromium

Magnesia-chrome refractories have been essential materials for application as wear lining in copper production furnaces for many years. Formation of hexavalent chromium (Cr(VI)) has been a major concern despite its admirable corrosion resistance in copper slag. Magnesia-chrome refractory specimens (9, 12, 15 and 18 wt% Cr2O3) with addition of Al2O3 and TiO2 were fabricated and subsequent corrosion tests using copper slag was conducted in air. The corrosion mechanism between magnesia-chrome refractories fabricated and synthetic copper slag were investigated by means of X-ray diffraction (XRD) and scanning electron microscope (SEM), and concurrent formations of Cr(VI) were assessed effectively by leaching test. All the magnesia-chrome specimens prepared are composed of periclase and composite spinel Mg(Al,Cr,Ti)2O4 phases after firing at 1700 °C. Densification of the specimens decreases with the increase in Cr2O3 content due to the increased volume expansion, while TiO2 addition can improve their densification as mass transfer is enhanced during the sintering process. The corrosion resistance of the specimens decreases slightly with the Cr2O3 content due to the increased apparent porosity, which would result in penetration of more corrosive slag at the initial stage of the corrosion test while a newly formed (Mg,Cu)(Cr,Fe)2O4 spinel dense layer between the slag and penetration layer effectively hinders further penetration of slag and well protects the specimens. The Cr(VI) in the specimens prepared increases obviously with the Cr2O3 added content, while the TiO2 addition can suppress the formation of Cr(VI) effectively and the copper slag can cause the formed Cr(VI) to be reduced further during the corrosion process. For all the specimens, concentrations of Cr(VI) in the leachates is much lower than the US-EPA limit of 100 mg/kg but exceeds the European limit of 2 mg/kg after the corrosion test.

Conductivity and giant permittivity study of Zn0.5Ni0.5Fe2O4 spinel ferrite as a function of frequency and temperature.

Ni0.5Zn0.5Fe2O4 was prepared by the solid state reaction route at different temperatures. The dielectric properties of spinel ferrites were investigated in the frequency range 50 Hz–10 MHz and in the temperature range 300–420 K. Conductance is shown to increase with increasing frequency and temperature. Impedance analyses indicated that the relaxation phenomenon is strongly dependent on temperature and frequency. The impedance plots displayed both intra- and inter-granular contributions. Electrical equivalent circuit was proposed to explain the impedance results. The decrease of giant permittivity values with the increase in frequency proves the dispersion in the low frequency range and is showing the Maxwell–Wagner interfacial polarization.

Crystal Structures and Magnetic Properties of Polyethylene Glycol (PEG-4000) Encapsulated Co0.5Ni0.5Fe2O4 Magnetic Nanoparticles

Nanocrystalline mixed spinel ferrite of Co0.5Ni0.5Fe2O4 magnetic nanoparticles (MNPs) has been successfully synthesized by coprecipitation method and encapsulated by PEG-4000 with various concentrations. X-Ray Diffraction (XRD) patterns showed that nanoparticles contained Co0.5Ni0.5Fe2O4 spinel ferrite with crystallite size of 14.9 nm. After PEG-4000 encapsulation particles size decreased became 7.7 nm. Interaction Co0.5Ni0.5Fe2O4 nanoparticles with long chain PEG-4000 caused the crystal growth trap. Lattice parameter and X-Ray density have no significant difference after encapsulated PEG-4000. The coercivity (𝐻𝑐) of Co0.5Ni0.5Fe2O4 was 214 Oe. The 𝐻𝑐 decreased after PEG-4000 encapsulation became 127 Oe, which is due to the decrease of crystallite size. The maximum magnetization (Mmax) of Co0.5Ni0.5Fe2O4 was 12.0 emu/g, and decreased after PEG-4000 encapsulation to 11.7 emu/g, because PEG-4000 is paramagnetic. After the concentration of PEG-4000 increased, then the amount of paramagnetic material increase which lead maximum magnetization decrease.

Improving of the Mg-Co nanoferrites efficiency for crude oil adsorption from aqueous solution by blending them with chitosan hydrogel.

The efficiency of the as-prepared Mg0.25Co0.75Fe2O4 spinel nanoparticles for adsorption of crude oil from aqueous solution was improved by blending them with chitosan hydrogel (CH) prepared using epichlorohydrin as cross-linker resulting (CH/Mg0.25Co0.75Fe2O4) nanocomposites. Mg0.25Co0.75Fe2O4 nanocrystals was prepared by the chemical co-precipitation method and characterized by using X-ray diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), and differential thermal analysis (DTA)/thermogravimetric analysis (TGA). DTA/TGA results showed that the net weight loss of the samples heated from room temperature up to 1000°C lies in the range 2.2-26.5% weight, where the maximum weight loss appeared at 100°C and 614°C. The blending nanocomposites prepared, were characterized by FT-IR and SEM micrographs. The effect of the nanoparticles ratio on the water uptake of nanocomposites and their capability to adsorb the crude oil was estimated by the gravimetric method. TEM results showed that the average nanoparticle size (Z) of Mg0.25Co0.75Fe2O4 is 30.06nm and the SEM illustrated the presence of a very clear and rough layer of pores which are homogenously arranged structures that could play an important role in the adsorption and stability of crude oil on polymers. The adsorption ability of crude oil from waste water on the CH/Mg0.25Co0.75Fe2O4 nanocomposites hydrogel was reported and it was found that the CH/Mg0.25Co0.75Fe2O4 with 95/5% ratio showed the improvement in the oil adsorption (72.5%) than the 0/100% one (50.2%). As a consequence, it is highly suggested that the potential of blending CH with Mg0.25Co0.75Fe2O4 to obtain CH/Mg0.25Co0.75Fe2O4 for enhancing crude oil adsorption in oily waste water treatment with a low cost.

Co-dopant affect on the structural, electrical and magnetic properties of zirconium and copper co-substituted Ni0.75Zn0.25Fe2O4 spinel ferrites synthesized by sol-gel method

The zirconium and copper co-substituted Ni0.75Zn0.25ZrxCuxFe2-2xO4 (where x = 0.05, 0.1, 0.15, 0.2) ferrites have been prepared by sol-gel auto-combustion method. The XRD patterns provide the evidence of single phase cubic spinel structure. The theoretical and experimental lattice parameters have resemblance with increase dopant concentration. The sintered density and porosity show the opposite trend with dopant concentration. The FT-IR spectrum of prepared samples reveal cubic spinel with Fd3¯m(Oh7) space group. The wave numbers of tetrahedral and octahedral sites show agnate trend. The dielectric constant and loss factors decreased with increasing dopant concentration. The saturation magnetization and net magnetic moment have the identical trend with increasing dopant concentration. The coercive field is decreased with increasing dopant concentration. The Y–K angles are increased with increasing dopant concentration. The Q-factor in prepared samples, exhibit narrower frequency bands with increasing frequency.

Structural, morphological and magnetic properties of divalent copper-substituted Co–Zn Nanoferrites

Nanocrystalline Co[Formula: see text]Zn[Formula: see text]Cu[Formula: see text]Fe2O4 spinel ferrites were prepared by autocombustion method with citric acid as fuel. Paramagnetic divalent copper ions substituted in place of ferromagnetic cobalt ions resulted in the modifications of structural and magnetic properties of the system. All samples were characterized with X-ray diffraction technique for structure determination. Crystallite sizes were calculated using Williamson–Hall plot and size–strain plots. Cation distribution and all other structural parameters were presented. Transmission electron microscopy measurements were done for x = 0 and x = 0.15 and they showed well-developed spherical particles with average sizes of 35 nm and 48 nm. Morphological studies were performed and grain growth was observed to be increased with copper concentration. EDAX measurements revealed the stoichiometric proportions of the samples as per the chemical composition. Mid-IR spectroscopy was used to characterize the spinel phase and displayed two characteristic absorption bands in all samples with a slight shift. M–H loops were recorded using vibrating sample magnetometer at room-temperature and highest saturation magnetization was observed to be 50.2 emu/g for the base (x = 0) sample. Magnetocrystalline anisotropy was discussed with the help of magnetocrystalline anisotropy constant K1.

Effect of Cu-doping on structural and electrical properties of Ni0.4−xCu0.3+xMg0.3Fe2O4 ferrites prepared using sol–gel method

ABSTRACTNi0.4−xCu0.3+xMg0.3Fe2O4 spinel ferrites were prepared by sol–gel technique. X-ray diffraction results indicate that ferrite samples have a cubic spinel-type structure with space group. The electrical properties of the studied samples using complex impedance spectroscopy technique have been investigated as a function of frequency at different temperatures. We found that the addition of copper in Ni0.4−xCu0.3+xMg0.3Fe2O4 ferrite system can improve its conductivity. Dielectric properties have been discussed in terms of hopping of charge carriers between Fe2+ and Fe3+ ions. For all samples, frequency dependence of the imaginary part of impedance (Z") shows the existence of relaxation phenomenon. The appropriate equivalent circuit configuration for modeling the Nyquist plots of impedance is of the type of (Rg + Rgb//Cgb).

Tuning of Magnetic and Optical Properties of Co0.8Zn0.2Fe2O4 Spinel Ferrite Thin Films Based on Post Annealing Temperature

This paper is dedicated to deposit zinc substituted cobalt ferrite (Co0.8Zn0.2Fe2O4) thin films on glass substrate using electron beam deposition technique. The effect of post annealing temperature on structural, magnetic, and optical properties of thin films has been investigated. Thin films have been characterized using x-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), vibrating sample magnetometer (VSM), UV-VIS spectroscopy, and spectroscopic ellipsometry (SE) analysis. The as-deposited thin films are amorphous in nature. After deposition, these thin films post annealed at different temperature ranges from 200 to 500 ∘C to enhance the crystallinity of films. The film post annealed at 200 ∘C is also amorphous in nature. As the post annealing temperature increases, the thin films become more crystalline. X-ray diffractometer and Raman analysis confirm the formation of cubical inverse spinel structure of thin films. The saturation magnetization of the thin films decreases with the annealing temperature due to the sites occupancy of cations between tetrahedral and octahedral. The reduction in coercivity is correlated with the anisotropy constant, but the anisotropy value is still high which is suitable to form stable magnetic storage memories. The band gap energy are decreased which is mainly attributed due to increase in grain size of the film. It is noted that the band gap energy of these thin films are higher than that of bulk material, so these may be suggested for use in wide band gap applications.

Crystal Structures and Magnetic Properties of Polyethylene Glycol (PEG-4000) Encapsulated Zn0.5Ni0.5Fe2O4 Magnetic Nanoparticles

Nanocrystalline mixed spinel ferrite of Zn0.5Ni0.5Fe2O4 magnetic nanoparticles (MNPs) has been successfully synthesized by coprecipitation method and encapsulated and PEG-4000 with various concentrations. X-Ray Diffraction (XRD) patterns showed that nanoparticles contained Zn0.5Ni0.5Fe2O4 spinel ferrite with the particles size of 15.2 nm. After PEG-4000 encapsulation, particles size decrease became 13.3 nm. Transmission Electron Microscopy (TEM) image showed that the nanoparticles still aglomerate after PEG-4000 encapsulation. The coercivity (Hc) of Zn0.5Ni0.5Fe2O4 was 50.7 Oe. The Hc decrease after PEG-4000 encapsulation became 47.9 Oe, respectively. It is due to the decrease of particle size. The saturation magnetization (Ms) of Zn0.5Ni0.5Fe2O4 was 18.4 emu/g, and decrease to 17.1 emu/g after PEG-4000 encapsulation. This is because PEG-4000 has paramagnetic properties.

Facile synthesis and enhanced microwave absorption properties of multiferroic Ni0.4Co0.2Zn0.4Fe2O4/BaTiO3 composite fibers

Multiferroic composite fibers composed of Ni0.4Co0.2Zn0.4Fe2O4 (NCZFO) spinel ferrite and BaTiO3 (BTO) have been successfully synthesized by a simple electrospinning and subsequent heat treatment. The effects of the BTO content on the structure, static magnetic performance, electromagnetic and microwave absorption properties of the as-prepared samples are thoroughly investigated. The electromagnetic parameters and microwave absorption performances can be readily and effectively tuned through controlling the molar ratio of the two phases. The sample of NCZFO/(40 mol%)BTO fibers shows the enhanced complex permittivity making it better in microwave absorption capability than the composite fibers with other compositions and the mixture of NCZFO fibers and BTO fibers. The microwave absorption values less than −10 dB can cover the entire 2–18 GHz frequency range over the absorber thickness of 2–7.5 mm, and the minimum reflection loss value reaches −65.6 dB at 15.7 GHz with a broad effective absorption bandwidth below −10 dB of 7.8 GHz ranging from 2.6 to 6.8 GHz and 13.7 to 17.3 GHz for a layer thickness of 5 mm. The enhanced absorbing ability for the optimal NCZFO/(40 mol%)BTO fibers arises from the good synergistic effect between magnetic and dielectric components within the quasi-one-dimensional space, the improved interfacial effect as well as the proper electromagnetic impedance matching.

Corrosion of high chromia refractory materials by basic coal slag under simulated coal gasification atmosphere

In this paper, dynamic corrosion experiment of a high chromia refractory interaction with basic coal slag under slagging gasifier conditions was conducted by using rotary drum corrosion test with the FactSage thermodynamic analysis. The microstructures and chemical compositions of the corroded samples were analyzed by scanning electron microscopy (BEI and EDS), and the corrosion mechanism was investigated by combining thermodynamic simulation and SEM analysis. The results show that the simulation results were consistent with the results of corrosion test. Reaction layer and penetration layer are formed from the surface to the interior of the sample after corrosion. The (Mg, Fe) (Al, Cr)2O4 spinel solution was formed in the reaction layer, which make the matrix structure become dense and change the overall structure of the particles’ uniformity. Corrosion of Cr2O3 aggregate is relatively weak by slag. The Cr2O3 dissolves into the slag through the formed spinel solution layer on the surface of aggregates. While, Cr2O3 and Al2O3 dissolve into molten slag through the spinel solution layer formed in the matrix. ZrO2 in the matrix directly dissolved into molten slag and penetrates inner the matrix with the penetration of the slag to form a ZrO2-free region. The liquid sintering of the matrix has happened in the melt, causes the structure of the penetration layer become dense, which is different from that of the original sample.

Frequency and temperature dependence of conductance, impedance and electrical modulus studies of Ni0.6Cu0.4Fe2O4 spinel ferrite

Ferrite with nominal composition Ni0.6Cu0.4Fe2O4 was synthesized using Pechini sol-gel method. The X-ray diffraction results indicate that the ferrite sample has a cubic spinel type structure with Fd3¯m space group without any impurity phase. The electrical properties of this ferrite using complex impedance spectroscopy technique have been carried out as a function of frequency at different temperatures. The total conductance curves for the sample are found to obey Jonscher power law (G(ω) = GDC + Aωn) with an increase of frequency exponent (n) as temperature increases. Frequency dependence of imaginary part of impedance (Z″) shows the existence of relaxation phenomenon in our sample. The impedance study using Nyquist representation revealed the appearance of semicircle arcs and an equivalent circuit of the type of (Rg + Rgb//ZCPE) has been proposed to explain the impedance results. Likewise, the analysis of the temperature variation of the imaginary part of modulus (M″) spectra confirms the existence of relaxation phenomena. Activation energies calculated from DC conductance, impedance and modulus spectra are in close agreement. This indicates that the relaxation process and electrical conductivity are attributed to the same defect.

Structural, optical and dielectric properties of polyaniline-Nio.5 Zno.5Fe2O4 nano-composites

Nio.5Zno.5Fe2O4 spinel ferrite was prepared by sol gel method. In situ polymerization method was used to synthesize polyaniline-Nio.5Zno.5Fe2O4 nano-composites having general formula (1-x)ferrite+(x)PANI where x = 0,0.3,0.5,1 (CP,CP1,CP2 and PANI). The effect of structural, optical and dielectric properties of the PANI- Nio.5Zno.5F2O4 nano-composites were investigated. XRD analysis confirmed that the Nio.5Zno.5Fe2O4 particles were successfully dispersed in the PANI matrix with single phase structure. The crystallite size of nano-composites increased with increasing spinel ferrite contents in the PANI matrix due to amorphous structure of PANI. Optical band gaps was calculated by using Tauc relation which found that optical band gradually decreases with the increasing amount of Nio.5Zno.5Fe2O4 in PANI. The dielectric constants (ε′,ε′′), dielectric loss (tanδ) and AC conductivity (Ϭac) were explained as a function of frequency (1kHz to 1MHz) which is described by Maxwell Wagner Model. The spinel ferrite-PANI composite are valuable as microwave absorbers because of their low cost, light weight and flexibility.

A Simple Wireless Power Charging Antenna System: Evaluation of Ferrite Sheet

We report a simple wireless power charging (WPC) antenna system (50 mm $\times40$ mm $\times0.1$ mm) for use in simulating power transfer efficiency ( $\eta $ ) with and without ferrite and a metallic object (battery case), thereby identifying suitable magnetic parameters and ferrite sheet thickness. The simulation results suggest that magnetic loss tangent (tan $\delta _{\mu }$ ) and permeability ( $\mu '$ ) need to be less than 0.05 and higher than 125 at 13.56 MHz, respectively, to achieve at least 75% of the transfer efficiency ( $\eta _{\mathrm {max}}$ ) of the WPC antenna without ferrite and the metallic object. Accordingly, we have fabricated Ni x Zn0.85– x Cu0.15Fe2O4 (x = 0.32 – 0.38) spinel ferrites using a one-step sintering process and obtained relatively high $\mu '$ of 169 and low tan $\delta _{\mu }$ of 0.1 with a nickel (Ni) concentration of 0.38. This magnetic loss is still too high to achieve 75% of the $\eta _{\mathrm {max}}$ value. In order to further reduce the magnetic loss, a two-step sintering process was used. The two-step sintered Ni0.38Zn0.47Cu0.15Fe2O4 shows $\mu '$ of 132 and a tan $\delta _{\mu }$ of 0.03 at 13.56 MHz, respectively. Therefore, this ferrite meets criteria identified by the transfer efficiency simulation and is a good candidate for 13.56-MHz wireless power transfer charging antenna system. In addition, our designed WPC system is capable of evaluating other magnetic materials that are suitable for WPC antenna applications.

Study of Structural and Magnetic Properties of Silica and Polyethylene Glycol (PEG-4000)-Encapsulated Magnesium Nickel Ferrite (Mg0.5Ni0.5Fe2O4) Nanoparticles

Mg0.5Ni0.5Fe2O4 has been successfully synthesized by using co-precipitation method. Two series of Mg0.5Ni0.5Fe2O4 silica encapsulated have been prepared by varying the concentration of silica and variation of PEG-4000 concentration. Analysis of X-Ray Diffraction (XRD) pattern showed that nanoparticles contained Mg0.5Ni0.5Fe2O4 spinel phase and γ-Fe2O3 phase with a particle size of 5.1 nm. The various of silica encapsulation give rise to produce a new phase of SiO2 and increase the particle size to 16.1 nm. PEG-4000 encapsulation affected to create a new phase of γ-FeO(OH), and reduce the particle size down to 4.5 nm. Fourier Transform Infra Red (FTIR) for Mg0.5Ni0.5Fe2O4 showed absorption peaks around 300-600 cm-1 which are M-O bond vibration. After silica encapsulation, there was new bond vibration typical of silica such as Si-O-Si (1049.28 cm-1), Si-OH (779.24 cm-1), and Si-O-Fe (570.93 cm-1). The PEG-4000 encapsulation creates a new vibration for typical of PEG-like of C-O (1103.28 cm-1) and C-H (925.83, 1481.33, and 2924.09 cm-1). Both of encapsulations series have M-O bond vibration indicating the presence of Mg0.5Ni0.5Fe2O4. After silica encapsulation, the coercivity of Mg0.5Ni0.5Fe2O4 decreased from 47 Oe to 10 Oe due to the decrease of particle size. Even though, the discrepancy of particle size as the effect of PEG-4000 encapsulation, the coercivity just slightly reduced to 46 Oe. The saturation magnetization of Mg0.5Ni0.5Fe2O4 decreased from 4.7 emu/g to 1 emu/g after silica encapsulation because diamagnetic SiO2. Otherwise, the saturation magnetization increased to 7.7 emu/g after PEG-4000 encapsulation because of domination of Mg0.5Ni0.5Fe2O4 phase ratio.

Synthesis, structural and complex impedance spectroscopy studies of Ni0.4Co0.4Mg0.2Fe2O4 spinel ferrite

ABSTRACTSpinel ferrite having composition Ni0.4Co0.4Mg0.2Fe2O4 was prepared by sol-gel method. X-ray diffraction result indicates that the ferrite sample has a cubic spinel type structure. FT-IR showed two absorption bands (ν1 and ν2) that are attributed to the stretching vibration of tetrahedral and octahedral sites. Complex impedance properties have been investigated in 200–420 K temperature range with varying frequency between 40 and 107 Hz. Frequency and temperature dependency of imaginary part of permittivity (ϵ″) and dielectric loss (tanδ) has been discussed in terms of hopping of charge carriers between Fe2+ and Fe3+ ions. Activation energy has been estimated from both temperature dependency of dc conductivity and relaxation time data, which indicates that the relaxation process and conductivity have the same origin. Nyquist plots of impedance show semicircle arcs for sample and an electrical equivalent circuit has been proposed to explain the impedance results.