Electrical Relaxation Research Articles

High temperature ac conductivity relaxations in dielectric ceramics: grain boundary/intergranular phase effects

The electric polarization and dc conductivity as two main factors cause electric relaxation in dielectric ceramic, which are difficult to be distinguished from each other at high temperatures. In this work, it is found that the two key factors can be separated via conjoint analysis of various complex planes such as complex dielectric permittivity, the impedance, the electric modulus, and the ac conductivity planes. Taking ZnO ceramics as a typical example, the ac conductivity relaxations caused by the long range and short-range migration of charge carriers are discussed as a function of frequency at high temperatures (433–473 K). Under the applied ac electric field, the migration of charge carriers within the ZnO ceramic can be restricted by two high-resistance barriers from grain boundaries and intergranular phases. These barriers result in two dispersion processes in conductivity response, which exhibit two relaxation peaks with activation energies of 0.75 eV and 0.89 eV. It was proposed that, in high temperature region, the ac conductivity relaxations of ZnO ceramic are the result of carrier migration localized between grain boundaries, and carrier migration localized between intergranular phases.

Electric modulus approach to the analysis of electric relaxation and magnetodielectric effect in reduced graphene oxide–poly(vinyl alcohol) nanocomposite

The polymers poly(vinyl alcohol) (PVA) is used as matrices to synthesize a nanocomposite with reduced graphene oxide (rGO). The structural and optical properties of the rGO and the nanocomposites (rGO–PVA) are studied by XRD, FTIR analysis, FESEM studies, Raman spectroscopy and UV–VIS absorption spectroscopy analysis. Interaction of PVA polymer chains with rGO is confirmed from FTIR study. The bandgap of the PVA and rGO–PVA nanocomposites has been studied from UV–VIS absorption spectrum. The refractive index and optical dielectric constants of PVA, GO, rGO and rGO–PVA nanocomposites have been discussed from optical spectrum analysis. The visual structures of the GO, rGO and rGO–PVA nanocomposites are observed from FESEM study. The electric modulus M*(ɷ) formalism used in the analysis enabled us to distinguish and separate the relaxation processes, dominated by marked conductivity in the e*(ɷ) representation. In the ceramics studies, the relaxation times are thermally activated and the dipole process has a clearly non-Debye behaviour. The relaxation process is described with the use of the activation energy of approximately EA = 0.12 eV and the characteristic relaxation time, τ0 = 2.07 × 10–7 s. The dielectric property of the nanocomposite (rGO–PVA) is studied in zero magnetic field and in magnetic field (H) up to 1.2 T. From these data, magnetodielectric effects are obtained as the variation of real (e′) and imaginary (e″) parts of complex dielectric constant with H at some frequencies. In our study at 100 kHz for the increase of H from zero to 1 T e′ decreases by 2.5% in rGO–PVA. This fact is indicative of the interaction between rGO filler particles and PVA polymer chains.

Understanding CO2 electrochemical reduction kinetics of mixed-conducting cathodes by the electrical conductivity relaxation method

Electrochemical reduction reaction is an important approach to utilize CO2 and convert it into valuable products. Exceptional reaction kinetics at a high temperature of solid oxide electrolysis cells (SOECs) attracts particular attention. In this work, we propose to investigate CO2-RR kinetics using a new theoretical method based on the electrical conductivity relaxation (ECR) technique on a typical mixed-conducting Sr2Fe1.5Mo0.5O6-δ (SFM) electrode. Three kinetic parameters that are commonly adopted in the typical electrochemical test experiments consisting of overpotential, current density and area-specific resistance (ASR) are derived. The overpotential resulted from the difference in the oxygen partial pressure is caused by the change of CO2 partial pressure, while current density from the surface reaction rate constant. Accordingly, area-specific resistance, as well as overpotential-current density relationship, can be derived. We believe that this work brings a new method to study the kinetic process of CO2 electrolysis and to evaluate the electrocatalyst activity of developed new electrode materials as well as to benefit the designing of novel electrode electrocatalysts for highly efficient solid oxide electrolysis cells.

Li-Ion Diffusion in Nanoconfined LiBH4-LiI/Al2O3: From 2D Bulk Transport to 3D Long-Range Interfacial Dynamics.

Solid electrolytes based on LiBH4 receive much attention because of their high ionic conductivity, electrochemical robustness, and low interfacial resistance against Li metal. The highly conductive hexagonal modification of LiBH4 can be stabilized via the incorporation of LiI. If the resulting LiBH4-LiI is confined to the nanopores of an oxide, such as Al2O3, interface-engineered LiBH4-LiI/Al2O3 is obtained that revealed promising properties as a solid electrolyte. The underlying principles of Li+ conduction in such a nanocomposite are, however, far from being understood completely. Here, we used broadband conductivity spectroscopy and 1H, 6Li, 7Li, 11B, and 27Al nuclear magnetic resonance (NMR) to study structural and dynamic features of nanoconfined LiBH4-LiI/Al2O3. In particular, diffusion-induced 1H, 7Li, and 11B NMR spin–lattice relaxation measurements and 7Li-pulsed field gradient (PFG) NMR experiments were used to extract activation energies and diffusion coefficients. 27Al magic angle spinning NMR revealed surface interactions of LiBH4-LiI with pentacoordinated Al sites, and two-component 1H NMR line shapes clearly revealed heterogeneous dynamic processes. These results show that interfacial regions have a determining influence on overall ionic transport (0.1 mS cm–1 at 293 K). Importantly, electrical relaxation in the LiBH4-LiI regions turned out to be fully homogenous. This view is supported by 7Li NMR results, which can be interpreted with an overall (averaged) spin ensemble subjected to uniform dipolar magnetic and quadrupolar electric interactions. Finally, broadband conductivity spectroscopy gives strong evidence for 2D ionic transport in the LiBH4-LiI bulk regions which we observed over a dynamic range of 8 orders of magnitude. Macroscopic diffusion coefficients from PFG NMR agree with those estimated from measurements of ionic conductivity and nuclear spin relaxation. The resulting 3D ionic transport in nanoconfined LiBH4-LiI/Al2O3 is characterized by an activation energy of 0.43 eV.

PbO effect on the oxygen reduction reaction in intermediate-temperature solid oxide fuel cell

Ag paste is often used in solid oxide fuel cells (SOFCs) as the current collector. This study investigates the effect of lead oxide (PbO), which is usually present in Ag paste, on the oxygen reduction reaction (ORR) at the typical electrocatalysts, lanthanum strontium cobalt ferrite (LSCF) and lanthanum strontium ferrite (LSF), for intermediate-temperature SOFCs. The chemical oxygen surface exchange coefficients are greatly increased by the deposition of PbO particles on the LSCF and LSF bar surfaces as demonstrated by the electrical conductivity relaxation technique. For example, at 800 °C, the deposition of 0.074 mg cm−2 PbO particles increases the coefficients from 4.68 × 10−5 to 7.2 × 10−4 cm s−1 and from 2.62 × 10−5 to 1.60 × 10−4 cm s−1 for LSCF and LSF, respectively. Furthermore, the infiltration of PbO into porous LSCF and LSF electrodes significantly improves the ORR as determined with AC impedance spectroscopy using symmetrical cells comprising of samaria-doped ceria as the electrolyte. When 5.88 and 5.67 wt % PbO is infiltrated into the porous backbone of LSCF and LSF electrodes, at 650 °C, the area specific interfacial polarization resistance (ASR) is reduced from 0.26 to 0.14 Ω cm2 and from 1.34 to 0.37 Ω cm2, respectively. The distribution of relaxation time (DRT) analysis suggests that PbO efficiently accelerate the charge transfer and oxygen incorporation processes.

Ionic Liquid (1-Ethyl-3-methylimidazolium Acetate) Plasticization of Chitosan-Based Bionanocomposites.

The structure and properties of different biopolymer composites based on chitosan and chitosan/carboxymethyl cellulose (CMC) are governed by multiple structure–property relationships associated with different phase interactions. Plasticization of these matrices with ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) played a dominant role, increasing the mobility of biopolymer chains as well as ions and associated dipoles but reducing biopolymer chain interactions, crystallinity, and thermal stability. These structural changes led to higher matrix ionic conductivity, shorter electrical relaxation time, and greater matrix ductility. The inclusion of graphene oxide (GO) and reduced GO (rGO) also influenced the structure and properties of these bionanocomposites by disrupting the biopolymer hydrogen bonding and/or polyelectrolyte complexation (PEC) and interacting with [C2mim][OAc]. The impact of GO/rGO was more evident for 20 wt % [C2mim][OAc], such as increased crystallinity and thermal stability of chitosan. PEC was hindered with excess (40 wt %) [C2mim][OAc] added and further hindered again when rGO was included. This study shows that the structure and properties of bionanocomposites are not just determined by the surface chemistry of GO/rGO but can also be influenced by multiple interactions involving plasticizers such as ILs and additional biopolymers.

Pelvic-floor relaxation techniques using biofeedback – more effective therapy for chronic prostatitis/chronic pelvic pain syndrome

Objective: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is characterized by pelvic pain and voiding symptoms, the management of which is challenging. The present study was designed to assess the efficacy of biofeedback and pelvic-floor relaxation treatment for CP/CPPS. Methods: A total of 84 patients diagnosed with CP/CPPS were randomly assigned to one of the two groups: conventional therapy (group A) and pelvic-floor muscle relaxation and biofeedback (group B). The Biofeedback and Electrical Stimulation apparatus was used for pelvic-floor muscle electrical stimulation and relaxation with biofeedback. National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scores were evaluated at the start of therapy, after 3 months of treatment and at 6 months (3 months after last treatment received). Results: At 3 months, patients in both groups had a significant decrease (improvement in symptoms) in NIH-CPSI scoring. However, at 6 months, only 19 (47.5%) patients in group A maintained a fall in NIH-CPSI score >6 compared with 37 (94.8%) patients in group B ( p<0.05). At 6 months, there was significant decrease in NIH-CPSI score in group B, whereas in group A, scores had increased (worsening of symptoms). Conclusions: Pelvic-floor muscle relaxation and biofeedback training is a safe and effective treatment for CP/CPPS with sustained efficacy.

Arrhenius Crossover Phenomena and Ionic Conductivity in Ionic Glass‐Forming Liquids

Herein, the relation between the Arrhenius crossover (AC) behaviors in the structural relaxation and the electrical conductivity relaxation is explored in terms of the Bond Strength–Coordination Number Fluctuation (BSCNF) model developed by the authors. For the ionic glass‐forming liquids and solution examined, Ca2K3(NO3)7, Ca2Rb3(NO3)7, ZBLAN20 and (LiCl)0.16(H2O)0.84, the electric conductivity at high temperature resembles the behavior of the high‐temperature structural relaxation. This mutual relationship suggests a similar origin of the AC behaviors for both, structural and electrical relaxation. The difference between them is reflected in the different temperatures that demarcate the AC behaviors. The implication of this difference to the occurrence of the high ionic conduction via the decoupling mechanism is discussed in terms of the BSCNF model and the fractional Stokes–Einstein law.

Toward a better understanding of low-frequency electrical relaxation — An enhanced pore space characterization

The relaxation phenomena observed in the electrical low-frequency range (approximately 1 MHz–10 kHz) of natural porous media such as sandstones are often assumed to be directly related to the dominant (modal) pore throat sizes measured, for instance, with mercury intrusion porosimetry. Attempts to establish a universally valid relationship between pore size and peak spectral induced polarization (SIP) relaxation time have failed, considering sandstones from very different origins and featuring great variations in textural and chemical compositions as well as in geometric pore space properties. In addition working with characteristic relaxation times determined in Cole-Cole or Debye decomposition fits to build the relationship have not been successful. In particular, samples with narrow pore throats are often characterized by long SIP relaxation times corresponding to long “characteristic length scales” in these media, assuming that the diffusion coefficients along the electrical double layer were constant. Based on these observations, three different types of SIP relaxation can be distinguished. We have developed a new way of assessing complex pore spaces of very different sandstones in a multimethodical approach to combine the benefits of mercury intrusion porosimetry, micro-computed tomography, and nuclear magnetic resonance. In this way, we achieve much deeper insight into the pore space due to the different resolutions and sensitivities of the applied methods to pore constrictions (throats) and wide pores (pore bodies). We experimentally quantify pore aspect ratios and volume distributions within the two pore regions. We clearly observe systematic differences between three SIP relaxation types identified previously, and we can attribute the SIP peak relaxation times to measured characteristic length scales within our materials. We highlight selected results for a total of nine sandstones. It seems that SIP relaxation behavior depends on the size difference of the narrow pore throats to the wide pore bodies, which increases from SIP type 1 to type 3.

Enhanced temperature stable dielectric property and energy-storage performance of (1-x)(0.66Bi0.5Na0.5TiO3–0.34Sr0.7Bi0.2TiO3)– xK0.5Nd0.5TiO3 lead-free relaxor electroceramics

In this study, (1-x)(0.66Bi0.5Na0.5TiO3–0.34Bi0.2Sr0.7TiO3)–xK0.5Nd0.5TiO3 (BNBST–xKNT) ceramics were designed and synthesized, and they present significantly enhanced dielectric temperature stability and energy storage properties. The BNBST–0.06KNT composition exhibits a remarkable dielectric stability, as reflected in its stable dielectric constant (△ԑ/ԑ150 °C < ±15%) over a broad temperature range (25–401 °C). BNBST–0.02KNT achieves a high energy storage density Wrec = 1.2 J/cm3 under 110 kV/cm with an energy storage efficiency η of 76.9%, and the improved energy storage property originates from the improved breakdown field strength and decreased hysteresis behavior. The electrical conductivity and relaxation behaviors of BNBST–xKNT were also analyzed via impedance spectroscopy.

FeO6 Octahedral Distortion Activates Lattice Oxygen in Perovskite Ferrite for Methane Partial Oxidation Coupled with CO2 Splitting.

Modulating lattice oxygen in metal oxides that conducts partial oxidation of methane in balancing C-H activation and syngas selectivity remains challenging. This paper describes the discovery of distorting FeO6 octahedra in La1-xCexFeO3 (x = 0, 0.25 0.5, 0.75, 1) orthorhombic perovskites for the promotion of lattice oxygen activation. By combined electrical conductivity relaxation measurements and density functional theory calculations studies, this paper describes the enhancement of FeO6 octahedral distortion in La1-xCexFeO3 promoting their bulk oxygen mobility and surface oxygen exchange capability. Consequently, La0.5Ce0.5FeO3 with the highest FeO6 distortion achieves exceptional syngas productivity of ∼3 and 8 times higher than LaFeO3 and CeFeO3, respectively, in CH4 partial oxidation step with simultaneous high CO2 conversion (92%) in the CO2-splitting step at 850 °C. The results exemplify the feasibility to tailor the active lattice oxygen of perovskite by modulating the distortion of BO6 in ABO3, which ultimately influences their reaction performance in chemical looping processes.

Caspase-11-mediated enteric neuronal pyroptosis underlies Western diet-induced colonic dysmotility.

Enteric neuronal degeneration, as seen in inflammatory bowel disease, obesity, and diabetes, can lead to gastrointestinal dysmotility. Pyroptosis is a novel form of programmed cell death but little is known about its role in enteric neuronal degeneration. We observed higher levels of cleaved caspase-1, a marker of pyroptosis, in myenteric ganglia of overweight and obese human subjects compared with normal-weight subjects. Western diet-fed (WD-fed) mice exhibited increased myenteric neuronal pyroptosis, delayed colonic transit, and impaired electric field stimulation-induced colonic relaxation responses. WD increased TLR4 expression and cleaved caspase-1 in myenteric nitrergic neurons. Overactivation of nitrergic neuronal NF-κB signaling resulted in increased pyroptosis and delayed colonic motility. In caspase-11-deficient mice, WD did not induce nitrergic myenteric neuronal pyroptosis and colonic dysmotility. To understand the contributions of saturated fatty acids and bacterial products to the steps leading to enteric neurodegeneration, we performed in vitro experiments using mouse enteric neurons. Palmitate and lipopolysaccharide (LPS) increased nitrergic, but not cholinergic, enteric neuronal pyroptosis. LPS gained entry to the cytosol in the presence of palmitate, activating caspase-11 and gasdermin D, leading to pyroptosis. These results support a role of the caspase-11-mediated pyroptotic pathway in WD-induced myenteric nitrergic neuronal degeneration and colonic dysmotility, providing important therapeutic targets for enteric neuropathy.

Experimental and computational investigation of PVDF–$$\hbox {BaTiO}_{{3}}$$ interface for impact sensing and energy harvesting applications

The interfacial polarization between PVDF and $$\hbox {BaTiO}_{{3}}$$ was studied using density functional theory calculations and atomic charge density analysis. A comparative study of dielectric relaxation, thermodynamic properties and impact analysis of the electrospun polyvinylidene fluoride (PVDF) and a 3 $$\%$$ $$\hbox {BaTiO}_{{3}}$$ –PVDF nanofibrous composite are presented. The frequency-dependent dielectric properties revealed the microstructural feature of the composite material. The impedance analysis and Nyquist plots showed a decrease in the bulk resistance of the composite compared to the pure PVDF. The temperature dependence of the electric modulus shows Arrhenius-type behavior. The electric loss modulus relaxation peak shifts towards the high frequency side which indicates a decrease in relaxation time and faster charge carrier dynamics. The observed non-Debye type dielectric relaxation in electric loss modulus follows a thermally activated process, which can be attributed to the polaron hopping effect. The particle-induced crystallization of the PVDF polymer is supported by thermodynamic properties from differential scanning calorimetric measurements. The observed increase in piezoelectric response from high strain rate impact sensing was attributed to the interfacial interaction between PVDF and $$\hbox {BaTiO}_{{3}}$$ .

Temperature and frequency dependent electrical conductivity and dielectric relaxation of mixed transition metal doped bismuth-phosphate semiconducting glassy systems

Two ternary and three quaternary glass nanocomposites with a general chemical formula 0.45Bi2O3 - 0.15P2O5 - (0.4-x) V2O5- xMoO3 (x = 0, 0.1, 0.2, 0.3, and 0.4) are synthesized through melt quenching method. Few nanophases Bi5PO10, V2O5, BiVO4, Bi12P2O23, Bi(PO3)3, Bi13Mo4VO34, Mo4O11, MoOPO4, Bi4MoO9, and BiP5O14 are superimposed within glass matrices acknowledged from XRD patterns. The Almond-West formalism is used to study the electrical conductivity of mixed transition metal-doped bismuth-phosphate glass nanocomposites. The semiconducting non-linear characteristics are established from the dc conductivity curve and the different values of activation energies in high and low-temperature regions. The dc conductivity of each glass nanocomposite has been explained by the Mott and Greaves's variable range hopping model. The reducing nature dc conductivity with the rise of MoO3 content is elucidated from the estimated values of small polaron hopping energy (Whop) and hopping distance (Rhop). Modified correlated barrier hopping model flawlessly defines the mechanism of ac conductivity as the value of power-law exponent reduces with temperature. The effect of temperature and frequency on the dielectric properties of the samples has been intensely investigated. Non-Debye type of relaxation process of dynamic conductivity is predicted and the relaxation time exhibits Arrhenius characteristics.

Characterizing the Resistance Relaxation of the Fabric-based Resistive Sensors Based on an Electro-mechanical Model

Resistance relaxation induced by viscoelastic ingredient materials remains one of the greatest challenges for soft resistive sensors to provide accurate measurements. However, most relative studies focused on mere experimental studies or based on empirical mechanical models, other than the underlying electro-mechanical mechanism of the resistance relaxation. Hence, this work proposed an electro-mechanical model of fabric-based resistive sensors by introducing strain-resistance properties for the elements in the 2nd order Zener model. It was found the proposed model can well represent the trend of resistance relaxation at different strain levels with coefficients of determination higher than 0.9950. Moreover, the parameters of the model, such as final resistance increment E0, 1st and 2nd order resistance relaxation E1 and E2 were observed increasing linearly with strain levels, which was then confirmed by theoretical derivations based on the proposed model. To demonstrate the validity of the model, 5 samples of fabric-based resistive sensors were tested. Resistance relaxations of the sensors at given strain level of 0.5714 were predicted and compared to measured, where a high determination coefficient of 0.95 and a small averaged relative error in resistance of only 5‰ were observed. Conclusion can be drawn that the proposed electro-mechanical model of fabric-based resistive sensors can not only provide satisfactory characterization of the resistance relaxation, but also inspire the characterization of electrical relaxation for other flexible sensors.

Electrical Conductivity and Relaxation Behavior Studies of Corning Glass By Impedance Spectroscopy

Impedance Spectroscopy was applied to study conductivity and dielectric relaxation behavior of Corning’s glasses. The electrical behavior of several glass composition was studied over a wide range of frequency (1Hz -1MHz) and temperature (RT-500C). The relaxation time were calculated by analysis of electrical modulus. The calculated activation energy associated with dielectric relaxation and activation energy of dc conductivity are similar. The obtained values of conductivity confirm dependence of conductivity on number and mobility of ions at glass with different composition. With increasing conductivity, the relaxation time decrease. It was observed, that through entire temperature range, the dielectric relaxation is governed by the same mechanism.

Ruddlesden-Popper-type Nd2-xNi1-yCuyO4±δ layered oxides as candidate materials for MIEC-type ceramic membranes

Series of Nd2-xNi1-yCuyO4±δ Ruddlesden-Popper-type oxides is obtained by auto-combustion synthesis method and systematically characterized concerning phase composition, formation of solid state solution, crystal structure, oxygen content, as well as regarding transport properties and oxygen permeability when applied as mixed conducting ceramic membranes. The A-site deficiency x is discussed in terms of structural stability and its effect on the oxygen content, with ongoing modification of total electrical conductivity observed. In selected Nd2-xNi0.75Cu0.25O4±δ oxides the dominating oxygen defects at high temperatures can be changed from oxygen interstitials to vacancies by the induced A-site deficiency, which affects bulk- and surface-related transport coefficients, as it is observed in electrical conductivity relaxation studies. The optimized Nd1.9Ni0.75Cu0.25O4±δ sinters having increased ionic conductivity, as well as fine, well-sintered microstructure allow to achieve one of the higher reported oxygen fluxes for CO2-stable Ruddlesden-Popper-based ceramic membranes (e.g. 0.49 mL cm−2 min−1 at ca. 880 °C for 1.05 mm thickness).

Low Frequency Dielectric Relaxation and Conductance of Solid Polymer Electrolytes with PEO and Blends of PEO and PMMA.

Solid polymer electrolytes are mixtures of polymer and inorganic salt. There are quite a number of studies dealing with the relationship between electric conductivity and structural relaxation in solid polymer electrolytes. We present a phenomenological approach based on fluctuation-dissipation processes. Phase heterogeneity appears in poly(ethylene oxide) (PEO) of high molecular mass and its blends due to crystallization and accompanying phase segregation. Addition of salt hampers crystallization, causing dynamic heterogeneity of the salt mixtures. Conductivity is bound to amorphous phase; the conductivity mechanism does not depend on content of added salt. One observes dispersion of conductivity relaxation only at low frequency. This is also true for blends with poly(methyl methacrylate) (PMMA). In blends, the dynamics of relaxation depend on glass transition of the system. Glassy PMMA hampers relaxation at room temperature. Relaxation can only be observed when salt content is sufficiently high. As long as blends are in rubbery state at room temperature, they behave PEO-like. Blends turn into glassy state when PMMA is in excess. Decoupling of long-ranging and dielectric short-ranging relaxation can be observed. Conductivity mechanism in PEO, as well as in blends with PMMA were analyzed in terms of complex impedance Z*, complex permittivity, tangent loss spectra and complex conductivity.

Dielectric behavior of single iron atoms dispersed on nitrogen-doped nanocarbon

We report the enhanced dielectric properties of iron atomically dispersed on nanocarbon. Theoretical simulations and calculations based on the Havriliak–Negami model and the first principles demonstrate that the increased dielectric property can be explained by the increased electrical conductivity and dielectric relaxations caused by the introduction of single iron atoms. Nanocarbon with single iron atoms exhibited enhanced electromagnetic wave absorption properties and could be further improved when being coupled with reduced graphene oxide. Our findings open a way for exploring high-performance materials with single metal atoms for practical applications in electromagnetic fields.

Synthesis and study of impendence spectroscopy properties of La0.6Ca0.2Na0.2MnO3 manganite perovskite prepared using sol–gel method

La0.6Ca0.2Na0.2MnO3 manganite was prepared using sol–gel method. Rietveld refinement of XRD pattern indicates that the prepared sample crystallizes in the rhombohedral \(R\overline{3}c\) structure. The impendence spectroscopy properties of the sample were studied by performing a series of measurements as a function of temperature and frequency of conductivity, dielectric constants, modulus, and impedance. From these measurements, the metal–semiconductor behavior was observed for the sample at a transition temperature of the order of 240 K. The studies of imaginary part of permittivity and tangent loss reveal that the prepared material may be a good candidate for low-frequency energy storage devices. An electrical relaxation phenomenon with non-Debye nature was observed in variations of imaginary parts of modulus and impedance. Electrical parameters deduced from the Nyquist plots analyses using an equivalent circuit reveal that the conduction process for the sample was caused due to the grain boundaries contribution.