Frequency Dependence Of Conductivity Research Articles

Frequency-dependent and capacitive tissue electrical properties in spinal cord stimulation models.

Models of spinal cord stimulation (SCS) simulate the electric fields (E-fields) generated in targeted tissues, which in turn can predict physiological and then behavioral outcomes. Notwithstanding increasing sophistication and use in optimizing therapy, SCS models typically calculate E-fields using the quasi-static approximation (QSA). QSA, as implemented in neuromodulation models, neglects the frequency dispersion of tissue conductivity, as well as propagation, capacitive, and inductive effects on the E-field. The reliability of QSA specifically for SCS has not been considered in detail, especially for higher-frequency SCS. We implemented a frequency-dependent finite element method (FEM) and solved a high- resolution RADO-SCS model with voltage-controlled (VC) and current-controlled (CC) stimulation to assess the impact of frequency-dependent conductivity (dispersion) and permittivity of spinal tissues on E-fields generated at three different spinal column locations (epidural space, spinal cord, and root) for frequencies spanning from 1 Hz to 10 MHz. Results were compared with predictions of QSA method, with varied conductivity values of purely resistive tissues. We further assessed the impact of frequency-dependent and capacitive tissue properties on spinal heating and distortion of the E-field waveform. Tissue-specific electric properties around the energized leads and mode of stimulation-control impacted the magnitude of E-fields. In the spinal cord, the VC-SCS E-field generated with the frequency-dependent and capacitive properties was comparable to the QSA with 2X epidural fat conductivity, whereas the CC-SCS generated E-field was minimally impacted by frequency- dependent and capacitive properties up to 10 kHz. Spinal cord heating predicted by frequency- dependent and capacitive tissue properties was comparable to the QSA conditions with VC-SCS, whereas with CC-SCS, there was no impact of the frequency-dependent and capacitive tissue properties in spinal cord heating. E-field waveform distortion in the spinal cord, with CC-SCS at 1 kHz-specific electrical properties, was significant when fat capacitance (permittivity) was increased by 10X, whereas with VC-SCS, there was no effect of tissue capacitance. Regardless of the mode of SCS, QSA was still valid in predicting SCS-induced E-field and heating at the spinal tissues- across α and β dispersion region of spinal tissue's dielectric spectrum for VC-SCS and up to 10 kHz for CC-SCS.

Dissipative split-charge formalism: Ohm's law, Nyquist noise, and non-contact friction.

The split-charge equilibration method is extended to describe dissipative charge transfer similarly as the Drude model, whereby the complex-valued frequency-dependent dielectric permittivities or conductivities of dielectrics and metals can be mimicked at non-zero frequencies. To demonstrate its feasibility, a resistor-capacitor circuit is simulated using an all-atom representation for the resistor and capacitor. The dynamics reproduce the expected charging process and Nyquist noise, the latter resulting from the thermal voltages acting on individual split charges. The method bears promise to model friction caused by the motion of charged particles past metallic or highly polarizable media.

The dielectric characteristics of spray deposited α-Si3N4:ZnO thin films: The nitride effect on frequency-dependent capacitance and conductance profiles

The study focused on the effect of α-Si3N4 doping on the electrical/dielectric properties of ZnO thin films. Both α-Si3N4 doped and additive-free ZnO thin films were coated on p-Si substrates via a spray deposition method to achieve this. The electrical (current density (J)-voltage (V)) and dielectric properties (capacitance (C), conductance (G), dielectric loss (tanδ), reel/imaginary part of dielectric permittivity (ε′ and ε″) and electric modulus (M′ and M″)) were determined for all samples by using dielectric spectroscopy (DS) method. On the other hand, scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS) analysis were performed to evaluate microstructure, X-ray diffraction (XRD) was used to define chemical composition and atomic-force microscopy (AFM) analysis was carried out to characterise the topology of the coating layers. The thickness/surface roughness was obtained as ∼82.5 nm/10.6 nm for undoped and ̴ 99.5 nm/10.4 nm for nitride-doped samples, respectively. The maximum capacitance value (C) was obtained as 275 pF at −3.0V and 200 Hz, and the optimal conductance (G) value was also found as 45 μS around 4.0V and 1 MHz in the nitride-doped sample. The average of α and τ values was calculated as 5.67 × 10−5 s, 0.146 and 4.49 × 10−5 s, 0.081 for nitride-doped and undoped ZnO, respectively. The increase in performance can be attributed to the homogeneous and almost equally-size distribution of the ZnO grain growth which is strongly controlled by α-Si3N4.

Strange Metal and Superconductor in the Two-Dimensional Yukawa-Sachdev-Ye-Kitaev Model.

The two-dimensional Yukawa-Sachdev-Ye-Kitaev (2D-YSYK) model provides a universal theory of quantum phase transitions in metals in the presence of quenched random spatial fluctuations in the local position of the quantum critical point. It has a Fermi surface coupled to a scalar field by spatially random Yukawa interactions. We present full numerical solutions of a self-consistent disorder averaged analysis of the 2D-YSYK model in both the normal and superconducting states, obtaining electronic spectral functions, frequency-dependent conductivity, and superfluid stiffness. Our results reproduce key aspects of observations in the cuprates as analyzed by Michon etal. [Nat. Commun. 14, 3033 (2023)NCAOBW2041-172310.1038/s41467-023-38762-5]. We also find a regime of increasing zero temperature superfluid stiffness with decreasing superconducting critical temperature, as is observed in bulk cuprates.

Borophosphate glass based electrolyte composite for high lithium ionic conductivity

The application requirements of solid-state lithium (Li) metal batteries are satisfied by the ionic conductivity of composite solid-state electrolytes, attributed to their minimal interfacial resistance. Herein, composite solid electrolytes were obtained by mixing a crystalline Li0.5La0.5TiO3 (LLTO) perovskite with different amount of 47Li2O-30B2O3-23P2O5 (LBP) glass phase. The results show that the crystal phase of the composite samples exhibit a tetragonal perovskite structure with a P4/mmm space group. Frequency dependent AC conductivity shows that composite containing 1 % LBP glass avoids the phenomenon of charge carrier blocking at low frequency and low temperature at the same time. The room temperature maximum total ionic conductivity was obtained for sample with 0.5 % LBP glass presenting a conductivity that is almost three times higher than that of pure LLTO. The factors influencing ionic conductivity are not only grain morphology and size, and activation energy, but also lithium content, and entropic effects contribute to the facility or difficulty with which Li+ can migrate into the LLTO solid electrolyte.

Crystallite Size Effects on Electrical Properties of Nickel Chromite (NiCr2O4) Spinel Ceramics: A Study of Structural, Magnetic, and Dielectric Transitions

The effect of sintering temperature on the structural, magnetic, and dielectric properties of NiCr2O4 ceramics was investigated. A powder X-ray analysis indicates that the prepared nanocrystallites effectively inhibit the cooperative Jahn–Teller distortion, thereby stabilizing the high-temperature cubic phase structure with space group Fd-3m. Multiple transitions are confirmed by temperature-dependent magnetization M(T) data. Moreover, the magnetization value decreases and the Curie temperature increases with a decrease in the crystallite size. The low-temperature-dependent real permittivity (ε′-T) for a NiCr2O4 crystallite size of 78 nm exhibits a broad maximum at 40 K that is independent of frequency. This establishes a correlation between electric ordering and the underlying magnetic structure. The temperature dependency of the dielectric constant at fixed frequencies for both NiCr2O4 crystallite sizes rises with temperature for a certain range of frequencies. A significant improvement is evident: the dielectric constant (ε’) at room temperature reaches approximately 5738 for the sample with 28 nm crystallites, while the 78 nm crystallite sample shows a noticeable drop to ε’~174. The frequency-dependent conductivity curves for both types of NiCr2O4 nanocrystallites have different conductivity values. The lower-crystallite-size sample demonstrates higher conductivity values than the 78 nm crystallite size one. This observation is attributed to the decrease in crystallite size, which increases the number of grain boundaries and, consequently, scatters a higher number of charge carriers.

Interface characteristic and performance optimization mechanism for HfOx-based RRAM devices

The HfOx-based resistive random access memory (RRAM) is extensively researched for next-generation nonvolatile memory because of its high integration and excellent compatibility with CMOS technology. The interfacial characteristics, including interface state and series resistance, which impact the HfOx-based RRAM performance. However, a quantitative analysis about interface state and series resistance at metal/hafnium oxide (HfOx) interface is still scarce. The interface state and series resistance are related to the interfacial layer and oxygen vacancy concentration. In this work, we use the Ti/HfOx/Pt structural RRAM device with different oxygen contents to control the interfacial layer and oxygen vacancy concentration at metal/HfOx interface. The series resistance at the HfOx/Pt interface in the low resistance state (LRS) is obtained using the Schottky model, while the interface state density and time constant at the Ti/HfOx interface in the high resistance state (HRS) are extracted by frequency dependence of conductance. The results indicate that the device uniformity is improved by reducing the LRS series resistance and HRS interface state density. Furthermore, the device endurance in the HRS deteriorates with the decrease of the interface state time constant. Overall, the RRAM device performance is optimized by modulating the series resistance, interface state density, and time constant.

Investigating structural, dielectric, and electrical characteristics of sol–gel synthesized perovskite ceramic Bi0.7Ba0.3(FeTi)0.5O3

The goal of this research is to create a perovskite ceramic with electrical and dielectric properties appropriate for energy storage, medical uses, and electronic devices. A bismuth ferric titanate, Bi0.7Ba0.3(FeTi)0.5O3, doped with barium and crystalline, was effectively synthesized at the A-site via sol–gel synthesis. A rhombohedral structure emerged in the R3́C space group, which was confirmed by room-temperature X-ray studies. An average grain size of 263 nm and a homogeneous grain distribution and chemical composition were confirmed by the results of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The study established a clear relationship between temperature, frequency, and the electrical properties of the material. Impedance spectroscopy and electrical modulus measurements, performed in the frequency range of 1 kHz to 1 MHz and at temperatures ranging from 200 K to 360 K, demonstrated a non-Debye type of relaxation. Furthermore, once the material was produced at various temperatures, its frequency-dependent electrical conductivity was examined using Jonscher’s law. The results demonstrate that barium doping significantly improves the electrical conductivity and dielectric properties compared to pure BiFeTiO₃. Over the complete temperature range, consistent conduction and relaxation mechanisms were discovered. These findings suggest that the chemical may find widespread applicability across a broad temperature range, including electrical fields and capacitors.Graphical

Polaron assisted hopping mechanism in microwave processed Nd doped second layered aurivillius SrBi2Nb2O9 ceramics

The polycrystalline Sr0.8Sn0.2Bi1.75Nd0.25Nb2O9 (NdSBN) was synthesized using the green synthesis microwave sintering method, which significantly reduced the processing parameters of the NdSBN ceramics. Orthorhombic crystal structure with A21am symmetry was revealed by Rietveld refinement study, whereas the doping-induced strain and crystallite size was studied using the Williamson Hall method. Crossectional SEM micrographs confirm the plate-like structure, with an average grain size of 273.7 nm. A diffuse type of phase transition was observed at 345 °C, which usually arises due to compositional fluctuations and mobile oxygen vacancies; further, the diffusiveness of the NdSBN was studied using Uchino and Nomura function, a modified version of Curie-Weiss law (CW). The frequency and temperature-dependent dielectric study of NdSBN ceramics display a Maxwell-Wagner relaxation with a high loss in a low frequency regime, possibly due to the presence of leakage current in the solid solution. Frequency dependent AC conductivity obeys Jonscher's power law, whereas DC conductivity supports polaron assisted hopping in NdSBN composition with dual activation energies of 0.55 eV and 0.75 eV, which correspond to electrons and ions, respectively. The non-Debye type relaxation mechanism in conjunction with negative temperature coefficient of resistance (NTCR) behavior was demonstrated by temperature dependent impedance spectroscopy, while modulus spectroscopy confirmed the multiple relaxation processes in NdSBN ceramics.

La3+ doped CaCu3Ti4O12 ceramics: Investigation of its microstructural and dielectric properties against varying sintering durations

This article reports the relationship between microstructure and dielectric properties of the title material were prepared through combination of solid-state and sol–gel methods and then sintered by varying durations. XRD indicates Im-3 space group with a body centred cubic structure, and Rietveld refinement analysis showed good fits for all samples, with R-factors below 10 % and GoF less than 2. The XPS analysis revealed the existence of Ca 2p, La 3d, Cu 2p, Ti 2p, O 1s, and C 1s retained their correct oxidation states. SEM results show grain sizes of 1.10 (±0.25) μm, 1.24 (±0.10) μm, and 1.75 (±0.31) μm for 8, 12, and 16 h of sintering, respectively. EDS analysis confirms the presence of Ca, Cu, Ti, La, and O, indicating the purity of the ceramics. As the sintering duration increases, grain enlargement consistently leads to higher εr values with very low tanδ. At a low frequency of 50 Hz, εr increases with sintering duration, reaching values of 5.65 × 103, 5.90 × 103 and 9.94 × 103. Meanwhile, tanδ remains significantly low (<0.1) at 1 kHz. The Nyquist plots demonstrate deviation from Debye type relaxation with NTCR behaviour. The frequency-dependent AC conductivity follows Jonscher’s power law, with activation energy values of 0.44 eV, 0.46 eV, and 0.49 eV for ceramics sintered for 8, 12, and 16 h, respectively.

The structural, magnetic and electrical properties of chromium doped calcium ferrite nanoparticles

Calcium ferrite nanoparticles doped with Chromium (10-50 mol %) are synthesized using the solution combustion method, employing citrus Lemon extract as a reducing agent, followed by a calcination process at 500oC. Various characterization techniques are employed on the calcined samples. The Bragg reflections resulting from Chromium doping confirm the formation of a singular orthorhombic calcium ferrite phase. Crystallite sizes determined using both Scherrer’s and W-H plot methods found to be decreases with increase in dopant concentration. The surface morphology showcases agglomerated nanoparticles with irregular shapes and sizes, accompanied by pores and voids. The energy band gap found to be increases with increase in dopant concentration from 2.82 to 2.93 eV. The hysteresis loop analysis provides magnetic parameters including saturation magnetization (Ms), remanence (Mr), and coercivity (Hc). As the dopant concentration increases, Ms and Hc found to be maximum at 30 mol% cr3+ concentration in CaFe2O4 NPs. Linear increase in frequency-dependent conductivity at lower frequencies was observed. The presence of semicircles at low frequencies signifies compliance with the Cole-Cole formula for impedance behavior. Additionally, a detailed discussion on dielectric properties is presented. Notably, the dielectric constant decreases from 4.2 to 2.74 with an increase in dopant concentration. These distinctive attributes position the samples as suitable candidates for memory devices as well as high-frequency device applications.

Frequency-dependent capacitance and conductance characteristics and current transport mechanisms of Schottky diodes with TPA-IFA organic interfacial layer

In this study, a Schottky barrier diode with an Al/TPA-IFA/p-Si structure was fabricated using spin coating and thermal evaporation methods. Using forward and reverse bias I–V measurement, we examined the key electrical characteristics of the Al/TPA-IFA/p-Si diode, including Φb, n, Rs, and Nss; we also estimated VD, NA, EF, ∆Φb, WD, Φb and Nss using C–V measurements under the different frequencies (10, 50, 100, 500 kHz, and 1 MHz) at room temperature. Using I–V data and the Thermionic Emission (TE) theory, basic electrical parameters such as ideality factor ( n ), and barrier height ( Φb ) values were computed as 3.01 and 0.716 eV. The fundamental diode parameters are highly frequency-dependent. It was also found that the series Resistance ( Rs ) values reduced with increasing frequency, but the barrier height ( Φb ) and the width of the depletion layer ( WD ) increased. It was found that when frequency increased, the diode capacitance reduced for our new Schottky-type diode. The diode’s potential conduction mechanisms were examined through the utilization of reverse lnI−V0.5 and forward lnI−V graphs. The transport properties of Al/TPA-IFA/p-Si diode are primarily governed by ohmic conduction, Space Charge Limited Current (SCLC), and Trap Charge Limited Current (TCLC) mechanisms at low, moderate, and high voltages, respectively. It was concluded that the Poole–Frenkel Emission (PFE) mechanism was dominant for the Al/TPA-IFA/p-Si diode. Ultimately, the findings confirmed that the TPA-IFA-based diode could be obtained for the electronic application.

Rietveld refinement, core level electron shell structure and frequency-dependent dielectric behavior of vanadium bismuth oxide microstructures

Solid-state reaction method was employed to synthesize a series of complex compound system V2-xBi2xO5-δ (0.01 ≤ x ≤ 0.04), and their electrical properties at room temperature were examined through impedance spectroscopy within the frequency range of 40 Hz to 10 MHz. The X-ray diffraction (XRD) is refined to obtain the complete crystallographic profile of the compounds. The frequency-dependent conductivity exhibited adherence to Jonscher's universal power law across all compositions. As the bismuth concentration increased from x = 0.01 to 0.04, both AC and DC conductivity showed a systematic increase. AC conductivity raised from 3.17 × 10−4Sm−1 to 4.3 × 10−4 Sm−1 at 10 MHz, while DC conductivity increased between 1.56 × 10−4Sm−1 and 2.28 × 10−4Sm−1. The dielectric constant (εr') decreased with increasing frequency, stabilizing around 100 kHz. The electric modulus peaks at higher frequencies, reflecting relaxation processes, and approaches zero at lower frequencies due to the absence of electric polarization.

Innovative enhancements in polymer nanocomposites: Integrating ZnO nanorods into Hydroxypropyl methylcellulose/Polyvinyl pyrrolidone blend for advanced energy storage devices

Polymer nanocomposites are promising for various industrial and scientific applications due to their flexibility, diverse functionalities, and unique properties. In this study, zinc oxide nanorods (ZnO NRs) were incorporated into a blend of polymers (Hydroxypropyl methylcellulose - HPMC and Polyvinyl pyrrolidone - PVP) using a solution-casting technique, with concentrations varying from 2 % to 8 % by weight. Transmission electron microscopy (TEM) revealed that the ZnO NRs had an average diameter of 140 nm and a length of 3.22 μm. X-ray diffraction (XRD) analysis showed reduced crystallinity in the samples as the ZnO NR content increased. Fourier-transform infrared spectroscopy (FTIR) indicated changes in vibrational peaks due to interactions between functional groups in the blend and the nanorods. The addition of ZnO NRs significantly influenced the optical bandgap energies and UV/visible light absorption spectra of the samples. The bandgap of the nanocomposites significantly decreased upon ZnO NR incorporation, with direct and indirect bandgaps ranging from 5.19 to 4.70 eV and 4.74–3.66 eV, respectively. Electrical conductivity and dielectric characteristics were assessed across frequencies ranging from 0.1 to 10 MHz, revealing increasing AC conductivity, dielectric permittivity, and dielectric loss with higher ZnO NR content. Notably, at 10 Hz, the electrical conductivity increased from 3.5 × 10⁻12 S/m to 3.62 × 10⁻10 S/m upon loading with ZnO NR. The combination of adjustable optical bandgaps, frequency-dependent AC conductivity, and a wide range of tunable permittivity highlights the potential of these HPMC/PVP-ZnO NR nanocomposites for developing flexible optoelectronic and energy storage devices.

Reduced trap state density in AlGaN/GaN HEMTs with low-temperature CVD-grown BN gate dielectric

In this Letter, low-temperature (400 °C) chemical vapor deposition-grown boron nitride (BN) was investigated as the gate dielectric for AlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MISHEMTs) on a Si substrate. Comprehensive characterizations using x-ray photoelectron spectroscopy, reflection electron energy loss spectroscopy, atomic force microscope, high-resolution transmission electron microscopy, and time-of-flight secondary ion mass spectrometry were conducted to analyze the deposited BN dielectric. Compared with conventional Schottky-gate HEMTs, the MISHEMTs exhibited significantly enhanced performance with 3 orders of magnitude lower reverse gate leakage current, a lower off-state current of 1 × 10−7 mA/mm, a higher on/off current ratio of 108, and lower on-resistance of 5.40 Ω mm. The frequency-dependent conductance measurement was performed to analyze the BN/HEMT interface, unveiling a low interface trap state density (Dit) on the order of 5 × 1011–6 × 1011 cm−2 eV−1. This work shows the effectiveness of low-temperature BN dielectrics and their potential for advancing GaN MISHEMTs toward high-performance power and RF electronics applications.

Structural arrangement, electroconductivical and electrochemical behaviours of solid amino acid-based electrodes

This paper presents the study on the structural dependence of the electroconductivity and electrochemical activity of model amino acids, aspartate and glycine, which are used as solid electrodes in hybrid capacitor systems. It has been established that the presence of carbonyl, aliphatic, and amide functional groups on the surface enhances the electrochemical activity and electrical conductivity. The frequency dependence of conductivity is typical for polymer compounds with a proton conduction mechanism, which is provided by the surface migration of the charge. It was found that deposition on the surface of carbon templates of the amino acids in the formation of biocomposites increases the number of active reaction centers and provides effective electronic charge transport. As a result, it leads to a significant increase in the contribution of pseudocapacitance and capacitance processes. The electrochemical activity was caused by the pseudocapacitive accumulation of charge due to the course of redox reactions with amino acids and capacitive accumulation of charge, which occurs with the participation of amino acids and carbon templates. It has been proven that the porous structure of the carbon nanotubes provides a more dispersed and uniform distribution of amino acids on the surface, which is ensured in the growth of pseudocapacitive charge accumulation.

Impact of CeO2 additive on the temperature and frequency-dependent relaxation and conduction mechanism of BNT-BT ceramic

Impact of CeO2 additive on the temperature and frequency-dependent relaxation and conduction mechanism of BNT-BT ceramic

Electrical transport and dielectric relaxation mechanism in Zn0.5Cd0.5Fe2O4 spinel ferrite: A temperature- and frequency-dependent complex impedance study

In the present study, the frequency-dependent dielectric relaxation and electrical conduction mechanisms in sol-gel-derived Zn0.5Cd0.5Fe2O4 (ZCFO) spinel ferrite were studied in the temperature range of 343–438 K. The formation of the ZCFO spinel ferrite phase with space group Fd3m was confirmed by X-ray diffraction analysis. The dielectric relaxation and electrical conduction mechanisms were studied using complex impedance spectroscopy (CIS). In the Nyquist plots, depressed semicircles were fitted with an equivalent circuit model with configuration (RGBQGB) (RGQG), signifying the contributions from grain boundaries and grains to the charge transport mechanism in the sample. The frequency-dependent AC conductivity was found to follow Jonscher's power law, and the frequency exponent term depicted the overlapping large polaron hopping (OLPH) model as the dominant transport mechanism. The activation energies for conductivity, electric modulus and impedance were calculated to identify the nature of the charge carriers governing the relaxation and conduction mechanisms in the prepared sample. Complex modulus studies confirmed the non-Debye type of dielectric relaxation, whereas tangent loss and dielectric constant analyses confirmed the thermally activated hopping mechanism of charge carriers in Zn0.5Cd0.5Fe2O4 spinel ferrite.

Investigation of Structural and Dielectric Properties of Double Perovskite Ho2NiMnO6 Compound

The fascinating and diverse properties of double perovskites (DP) materials have attracted attention due to electrical, magnetic and structural properties. Due to their potential for usage in capacitive devices, memory devices, tuneable microwave filters, and other devices, the DP recently gained a lot of scientific interest. It is well known that these compounds demonstrate magnetoresistance and magnetocapacitance near ambient temperature. The DP compound (Ho2NiMnO6(HNMO) was prepared by conventional solid-state reaction method. The X-ray diffraction (XRD) analysis confirms the structure is monoclinic with the space group P21/n. The phase formation was further verified via FTIR spectral studies. FESEM was employed to investigate the morphology of the sample. Frequency-dependent dielectric constant, dielectric loss and conductivity were investigated at room temperature from 1000[Formula: see text]Hz to 1[Formula: see text]MHz.

Effect of Fe3+ ions substitution on electrical and dielectric properties of MgFexCr2-xO4 (x = 0, 0.2, and 0.4 mol%) chromites prepared by solution combustion method

This paper reports the structural, dielectric and electrical properties of Fe3+ ions substituted magnesium chromite with composition MgFexCr2-xO4 (x = 0, 0.2, and 0.4 mol%) synthesized via solution combustion method. The structural analysis was done by XRD pattern which confirmed the formation of cubic crystal symmetry of the samples with Fd-3 m space group. The value of lattice parameters of MgFexCr2-xO4 chromites slightly increased with increasing concentration of Fe3+ ions. The TEM (Transmission electron microscopy) micrographs at different magnifications showed the spherical particles of the sample and average particle size was found to be ≈ 56.22 nm. The dielectric parameters (dielectric constant and dielectric loss) and ac conductivity were investigated in the frequency range of 100 Hz–100 kHz and temperature range of 50 °C–350 °C. The dielectric studies showed that the dielectric parameter decreases in high frequency range which can be explained by Maxwell-Wagner type of space charge polarization. The dielectric constant increases with increasing concentration of Fe3+ ions due to increase in polarization. The frequency and temperature dependent ac conductivity was studied and found that the conductivity value increases with an increase in frequency and temperature, which followed the Jonscher's universal power law. The ac conductivity decreases with increasing Fe3+ ions due to formation of grain boundary defect barrier. The non-Debye type relaxation behavior of the MgFexCr2-xO4 samples was confirmed by the Cole-Cole plot. The obtained result shows the capability of magnesium chromite for fabrication of micro-electronic devices, sensors, and other electronic devices.