Ac Conductivity Spectra Research Articles

Co3+ Doped CdFe2O4 Nanoparticles: Structural, Optical, Magnetic, and Electrical Properties

Through the citrate-gel auto-combustion technique, we synthesized Co-doped cadmium nano ferrites (NFs) with the formula CoxCd1−xFe2O4 (where 0 ≤ x ≤ 1.0 with increments of 0.2). The synthesized materials underwent comprehensive analysis utilizing X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy. Magnetic and electrical properties were evaluated using a vibrating sample magnetometer and LCR meter, respectively. XRD analysis confirmed the spinel phase structure and FD3M space group. SEM analysis revealed agglomerations of nanoparticles and grain boundaries. Elemental analysis of the synthesized nanomaterials was provided by energy dispersive spectroscopy. FTIR spectroscopy identified two main broad bands corresponding to the tetrahedral (A) and octahedral (B) sites, confirming the spinel structure. Magnetic properties such as magnetic saturation, coercivity, and remanent magnetization were characterized using VSM. Additionally, the LCR meter assessed frequency and temperature-dependent dielectric parameters, including AC conductivity (σAC), dielectric permittivity, dielectric loss (tan δ), and impedance spectra. An increase in AC conductivity (σAC) was observed with increasing temperature and frequency.

Scaling behavior of AC conductivity and modulus spectra of K2NiO4-type Sr2TiO4

Scaling behavior of AC conductivity and modulus spectra of K2NiO4-type Sr2TiO4

Investigation of the relationship between morphology-electrical transport phenomena in iron-doped quaternary glass nanocomposite

The Fe doped nano nanocomposite glassy system xFe·(1-x)·(0.3 V2O5·0.2MoO3·0.4CdO·0.1ZnO) (x = 0.2, 0.3, and 0.4) has been studied by different techniques. Lattice strain (ɛ) increases with increasing iron (x) content in the glass system, which facilitates the enhancement of electrical phenomena such as transport using the polaron hopping mechanism. The AC conductivity spectra at different temperatures have been computed using Almond–West formalism and a modified correlated barrier hopping model. AC, as well as DC conductivity, have increased with increasing Fe content in compositions. The DC activation energies are found to be 0.53, 0.48, and 0.44 eV for the values of x = 0.2, 0.3, and 0.4 respectively. Both DC activation energy (Eσ) and activation energy (EH) for hopping frequency have decreased with Fe content. AC conductivity scaling data has explored that the common electrical relaxation mechanism is temperature-independent as well as composition-dependent.

Synthesis and electrical characterization of Sb modified lithium bismuth titanate

Sb-modified lithium bismuth titanate Li0.5Bi0.3Sb0.2TiO3 is prepared following the mixed oxide method. The development of a new compound with a single-phase orthorhombic crystal structure is approved from the XRD analysis at environmental temperature. The electrical behavior like dielectric and electrical conductivity are analyzed in a wide temperature as well as frequency range by the impedance analyzer, which exhibits that these properties effectively depend on frequency and temperature. The ac conductivity versus temperatures plots obeys the Arrhenius relation and confirm the presence of the mixed type of conductivity process like space charge conductivity created from oxygen ion vacancies, ionic-polaronic conductivity, and so on, in the sample. Ac conductivity versus frequency spectra is as per Jonscher’s Universal Power law.

Electrical Transport Properties and Hopping Mechanism of ZrCuSiAs Type Compound GdFeAsO

Abstract Iron-based ceramic GdFeAsO has been prepared using the solid-state reaction method. This material exhibits unique properties, showing superconductivity at extremely low temperatures and behaving as a semiconductor at high temperatures. Raman spectroscopy revealed various Raman active modes in the sample. UV-visible spectroscopy was employed to study the optical properties of the material in the wavelength range of 200-800 nm. Using Tauc's plot, the optical band energy values of the sample were estimated to be approximately 2.78 eV. The electrical characterizations have been performed through an impedance analyzer. Additionally, the sample displayed negative temperature coefficient of resistance behavior and positive temperature coefficient resistance. The thermistor parameters are evaluated using the bulk resistance at various temperatures. This opens up potential uses for thermistors in devices like fuses and temperature sensors. The ac conductivity spectrum of the sample followed both Jonscher's universal power law and the Arrhenius equation. The activation energy was calculated for different temperature regions. The correlated barrier hopping model is used to analyze the electrical conduction mechanism in the sample. This study provides insights into the unique electrical and optical properties of the GdFeAsO ceramic and sheds light on its potential applications in various fields.

Investigation of Sn and Zr co-doped Ba0.5 Sr0.5 TiO3 for dielectric, impedance and conductivity behaviour in temperature and frequency region of measurement

In this report, we are presenting the effect of B-site co-doping with Sn and Zr (2% each) on frequency and temperature-dependent dielectric and electrical properties of Ba0.5Sr0.5TiO3 (BST). The desired compound is synthesised following solid-state reaction route and the structural and micro-structural study of the resulting compound is done using X-ray diffractometer (XRD) and scanning electron microscope (SEM) technique. XRD study revealed that the parent structure of BST is mostly retained after co-doping. SEM micrograph analysis presented dense packing of grains of different sizes distributed all over the volume of compound formed. The compound was found to have a moderate value of dielectric constant and low tangent loss along with a near stable response of these dielectric properties over the studied frequency range, suggesting its possible application in tuneable matching networks and frequency agile antennas. Electrical properties study suggested a non-Debye type electrical response with a thermally activated conduction mechanism occurring in the material. The dependence of conductivity with temperature showed negative temperature coefficient of temperature behaviour of the compound and the ac conductivity spectrum followed Johnscher’s power law. The variation of exponent with temperature suggested correlated barrier hopping conduction mechanism in the material.

Effect of lattice disorder on charge transfer in lead molybdate crystals

*e-mail: tbochkova@meta.uaElectrical properties of PbMoO4 crystals, grown from the stoichiometric charge and non-stoichiometric charge with an excess of MoO3, are studied and compared in this work. The crystals are grown by Czochralski method in the direction at an angle of 30° to [100] axis in (001) plane. The single crystals are free from gas bubbles, cracks and have a weak yellowish color. It is found that the addition ofMoO3 excess (0.5 mol.%) to the stoichiometric charge notably increases the crystal lattice disorder. It is assumed that the appearance of lead ion vacancies plays the main role in the structural disordering. An increase of conductivity in DC and AC field, changes of current-voltage characteristics and AC-conductivity spectra are interpreted based on the model of hopping conductivity in disordered systems.

Clean energy storage device derived from biopolymers with moderate charge-discharge cycles: Structural and electrochemical properties

This work explores a green biopolymer (GBP) energy storage system to address the growing problem of microplastics that can harm our health. A GBP was made using solution casting with chitosan (CHN) and starch from potato (SPC) as the polymer hosts. Sodium thiocyanate (NaSCN) as Na+ cation provider and glycerol as an environmentally friendly plasticizer were mixed with CHN:SPC host polymers to prepare GBP electrolytes. The electrochemical impedance spectroscopy (EIS) results confirm the boost in DC conductivity. From the AC conductivity spectra, regions ascribing to EP and DC contributions are demonstrated. X-ray diffraction (XRD) and FTIR characterization provide evidence of salt dissociation and amorphous phase improvement. The determination of the ion fraction was achieved by means of TNM. The electrochemical stability of the conducting film was observed to be maintained up to 2.75 V. Cyclic voltammetry (CV), revealing no sign of charge transfer occurring through Faradaic processes at the interface between the electrode and electrolyte. The galvanostatic charge–discharge (GCD) plot displayed a triangular pattern, indicating a low voltage drop and a notable specific capacitance of 70 F/g. Moreover, the EDLC (electrical double-layer capacitor) exhibited an average power density of 1120 W/kg and an energy density of 9.11 Wh/kg.

Investigation of charge-carriers dynamics and sub/super-linear response for La0.8Na0.2-x□xMnO3 (x = 0 and 0.1) perovskite ceramics

La0.8Na0.2-x□xMnO3 (x = 0 and 0.1) compounds were prepared by solid-state reaction. XRD patterns were used to check the structural properties. Experimental results were discussed in terms of different theoretical approaches. The temperature dependence of DC-conductivity displays the presence of a metal-semiconductor transition for x = 0 and 0.1. The introduction of 10%-vacancy provokes a significant increase in the conductivity. The electrical conductivity is explained by many kinds of hopping each one is pronounced in a different temperature region. Two deviation temperatures are observed. These temperatures coincide with the ANC temperatures and the change in the conduction process. For x = 0.1, the Nyquist diagrams shows the presence of a high frequency inductive behavior. AC-conductivity spectra obey to the JPL and DJP. Then, SPL and NCL behaviors appear at high frequency range. The power "s" presents the contribution of numerous conduction models. The scaling behavior reveals that the conductivity spectra obey to the TTS principle.

Deep insights into morphological, structural and dielectric properties of BaTi0.5 (Cr0.33Mo0.17) O3 ceramics

In our present paper, the morphological, structural and electrical properties of chromium-doped BaTiO3 ceramics were investigated. BaTi0.5 (Cr0.33 Mo0.17)O3 was prepared by the sol-gel technique. Tetragonal phase with P4mm space group was observed by X-ray diffraction analysis. An excellent agreement between the calculated and the observed model was verified by Rietveld refinement. A polycrystalline compound with a particle size of 1.96 μm was identified using scanning electron microscopy. The electrical conductivity graph is divided into two regions in the frequency interval 102–106 Hz over the temperature range 480–640 K. The Ac conductivity spectrum follows the Jonscher's law. The conductivity mechanism in the studied temperature range can be explained by the Non-overlapping Small Polaron Tunnel (NSPT) model. The imaginary parts of impedance show that the maximum value of Z″ decrease with temperature rise, reflecting the progressive loss of insulating properties. In addition, the peaks of Z″ shifted to higher frequencies, indicating relaxation behaviour. Furthermore, the real part of Z″ decreased with temperature and frequency increase, indicating Negative Temperature Coefficient Resistance (NTCR) behaviour. The complex impedance plot showed large semicircular arcs corresponding to the merging of two semicircles due to grain and grain boundary contribution. Examination of the impedance and modulus normalization curves revealed a shift in both peaks, indicating the existence of a short moving carrier. The exponent “n" increased with temperature increase, which proves the existence of the Non-overlapping Small Polaron Tunnel (NSPT) model in the studied temperature range.

Effect of Sr doping on electronic transport properties of SnS2 hexagonal nanoplates

In this work, the electronic transport properties of SrxSn1-xS2 (x = 0, 0.02, 0.04, 0.06 and 0.08) nanoplates synthesized by hydrothermal method have been reported. AC conductivity, electric modulus and impedance spectra nanoplates have been studied in frequency and temperature ranging from 1Hz to 1 MHz and 313K–453K, respectively. AC conductivity data of the SrxSn1-xS2 nanoplates obeys the Almond-West relationship. In SrxSn1-xS2 nanoplates conduction governs by overlapping large-polaron tunnelling (OLPT), quantum mechanical tunnelling (QMT) and small polaron quantum mechanical tunnelling (SPQMT) mechanisms for x = 0, x = 0.02 and x = 0.04, 0.06 and 0.08, respectively. A modified KWW model has been used to understand the electric modulus behaviour of SrxSn1-xS2 nanoplates. The observed scaling behaviour of the imaginary component of the electric modulus supports the assertion of frequency exponent (s) with temperature about the conduction mechanism. The Nyquist plots are well-fitted with a double R-CPE model. The activation energy values estimated from conductivity (0.68–0.73 eV) and electric modulus (0.69–0.72 eV) analysis are in coherence.

Comparative analysis of the structural, optical, mechanical, and electrical properties of PMMA/PU blend‐based nanocomposites with FeVO4 nanofiller for energy storage devices

AbstractThe best materials for enhanced energy storage capacitors in electrical systems are polymer nanocomposites films. Therefore, using the solution casting approach, we created a unique series of FeVO4 nanofiller‐embedded polyurethane (PU) and polymethyl methacrylate (PMMA)‐based composites. Various techniques were used to describe the prepared films. XRD spectra were used to assess the crystallinity and crystallite size of nanocomposites. The XRD spectra were used to assess the crystallinity and crystallite size of nanocomposites. With rising nanoparticles (NPs) content up to samples with 1.5 weight percent of FeVO4, XRD demonstrated an increase in the amorphous phase of the polymer mixture, which was further supported by UV–Vis measurements. FTIR was used for determining the complexation of the FeVO4 with the polymer mixture. Calculations were used to determine optical properties such as the Urbach energy and energy bandgap. With a rise in FeVO4 NP concentration, the energy bandgap decreases while the Urbach energy increases. All samples' AC conductivity spectra exhibit Jonscher's power law (JPL) behavior. Studies on dielectric permittivity and electric modulus have also been conducted in order to comprehend the charge storage characteristics and conductivity relaxation. Whereas the frequency‐dependent increase in AC electrical conductivity, the ε′ and ε″ of PU/PMMA–FeVO4 nanocomposites drop with the rising of the electric field frequency. The high level of FeVO4 was shown to improve the AC conductivity, ε′ and ε″ values of the nanocomposites. Tensile strength was improved by 38% with the addition of FeVO4 NPs into the PU/PMMA blend. Experimental outcomes show that these polymer nanocomposites materials are multifunctional and can be used as low‐permittivity nanodielectric insulators and substrates to design the next generation of flexible electronic devices and also there can be used to create a variety of advanced optoelectronic and organic electronic devices.

Distinct dominant dielectric relaxation mechanisms in CaCu3Ti4O12 – LaMO3 (M = Mn and Fe) perovskite oxide solid solution

Two synthesized perovskite oxide solid solutions, CaCu3Ti4O12 – LaMnO3 and CaCu3Ti4O12 – LaFeO3, possess a crystalline structure embracing an amalgamation of two distinct phases, namely, hexagonal and orthorhombic phases in CaCu3Ti4O12 – LaMnO3 and cubic and orthorhombic phases in CaCu3Ti4O12 – LaFeO3. Examination of dielectric properties reveals colossal dielectric constant (εr), the peak magnitude of εr at 1 kHz being approximately 6×103 and 2.5×104 for Mn and Fe based compound, respectively. Further, complex impedance investigation (CII) establishes the activation energy (Ea) of grains (0.21 eV and 0.07 eV for Mn and Fe based solid solution, respectively) and grain boundaries (0.19 eV and 0.19 eV for Mn and Fe based solid solution, respectively). The deviation in Ea of grains and grain boundaries, as established through CII, in both, Mn and Fe based samples validates the existence of Maxwell-Wagner (M − W) relaxation. The AC conductivity spectrum for both the samples obeying the Jonscher's universal power law (JUPL): σ(ω,T)=σdc+Aωn. The Ea of bulk samples (0.37 eV and 0.19 eV for Mn and Fe based solid solution, respectively) authenticates predominant M − W relaxation (interfacial polarization) with polaron hopping playing the secondary role in Mn based sample, while both, polaron hopping and M − W relaxation being identical contributors towards dielectric nature of Fe based sample.

Ionic transport and segmental dynamics in poly(ethylene oxide) based polymer electrolytes: Dependence on molecular weight of host polymer matrix

We have investigated the ion transport and segmental dynamics in poly(ethylene oxide) (PEO) and sodium tetrafluoroborate (NaBF4) salt based solid polymer electrolytes as a function of molecular weight of PEO polymer matrix at a fixed salt concentration (EO/Na = 18) using broadband dielectric spectroscopy. The molecular weight (Mv) of PEO polymer matrix was varied from 1 × 105 to 6 × 105 g/mol. The ionic conductivity of the PEO based electrolytes obtained from the complex impedance plot showed a correlation with the glass transition temperature, crystallinity and ion diffusion coefficient. The AC conductivity spectra were analyzed by using the universal power law model, except the low frequency region, where the electrode polarization contribution was dominant. The temperature dependence of ionic conductivity and the hopping frequency followed the Vogel-Tammann-Fulcher (VTF) relation, indicating a coupling between the ion transport and the segmental dynamics of polymer chains. The segmental dynamics was investigated using the derivative dielectric constant spectra. The modulus spectra were well described by the Havriliak-Nigami and the Kohlrausch-Williams-Watts functions. The temperature dependence of the conductivity relaxation time also followed the VTF relation. The ion transport in PEO based polymer electrolytes with higher molecular weight was found more cooperative than that of the other polymer electrolytes.

Formation of silver particles in [PVA:CS:PEG]-AgNO3 based biopolymer electrolyte membranes: Structural and electric transport properties study

[Chitosan (CS)-poly(vinyl) alcohol (PVA)-polyethylene glycol (PEG-200)]+xwt% silver nitrate (AgNO3) (x = 0, 10, 20, 30, 40) based biopolymer blend electrolytes (BPBEs) were prepared using solution casting method. FTIR results show the interaction of Ag+/NO3− with the constituents of polymers CS/PVA. XRD results reveal that the amorphousness increases with increasing AgNO3 concentration. Optical morphological (OM) images show that the silver, Ag(o) particles are agglomerated on the surface of the membrane. Temperature dependent dc conductivity (σdc) and dielectric relaxation frequency (fr) for BPBEs follow the Arrhenius type behavior and the sample containing 30 wt% salt has optimum dc conductivity, σdc∼1.7×10−4 S/cm at 30oC with lowest activation energy∼ 0.16 eV. The ac conductivity spectra follow the Jonscher's power law (JPL) with power law exponent, s > 1. The scaling of AC conductivity and loss tangent (tanδ) spectra were performed with respect to temperatures/concentrations of salt. The dielectric permittivity study reveals that the electrode polarization effect predominates at low frequencies. The Ionic Transference Number (ITN) measurement was used to determine the nature species of charge carrier, either ionic or electronic. The linear sweep voltammetry (LSV), result shows that 30% AgNO3containing sample has the electrochemical stability window (ESW) ∼+1.5 to -1.5 V.

Modification and development in the microstructure of PVA/CMC-GO/Fe3O4 nanocomposites films as an application in energy storage devices and magnetic electronics industry

We used casting method to create nanocomposites films from carboxymethylcellulose (CMC)/polyvinyl alcohol (PVA) and GO/Fe3O4 as nanofiller. Various analyses such as structural, vibrational, optical, conductivity, dielectric and magnetic studies reveal promising properties of the prepared polymer nanocomposites (PNCs) films. The amorphous phase of the polymer blend increased with increasing GO/Fe3O4 concentration up to samples containing 0.05%GO/1%Fe3O4 nanofiller, according to X-ray diffraction. The complexation of the nanofiller with the polymer blend's –OH, –COO, CO, and –CH groups through a coordinate bond/hydrogen bond was confirmed by Fourier-transform infrared analysis. While the Urbach energy showed a trend in the opposite direction, the optical bandgap gradually turned red as the nanofiller concentration increased. The interaction of GO/Fe3O4 ions with the CMC/PVA matrix is attributed to the changes in optical properties of CMC/PVA. The Jonscher's power law (JPL) is observed in all samples' ac conductivity spectra. To comprehend the charge storage competences, research of dielectric permittivity was also conducted. A study of dielectric permittivity was also conducted to comprehend the charge storage competences. While AC conductivity increases with frequency, dielectric characteristics decrease with frequency. With the addition of nanofiller, AC conductivity and dielectric characteristics increase. For 0.05%GO/1%Fe3O4 nanofiller loaded sample, the highest AC conductivity and dielectric constant were attained. The results of vibrating sample magnetometer (VSM) revealed that synthesized nanocomposite films exhibit superparamagnetic features. The unique features of CMC/PVA-GO/Fe3O4 films enable their employment in a variety of industries, including magnetic electronics, energy storage devices, and optoelectronics.

Structural, optical, electrical, and dielectric relaxation properties of rare earth containing sodium bismuth titanate [formula omitted] perovskite: Effect of ionic radius

The main focus of this work is to study the effect of the ionic radius of different rare earth dopant cations RE3+ (RE = La, Sm, Dy, and Ho) on structural and various physical properties of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) based perovskite nanomaterials. The X-ray diffraction data indicate the successful formation of the rhombohedral phase (space group R3c) of NBT nano perovskite incorporated with various rare earth ions in Bi-site. The lattice parameters were found to increase linearly with the ionic radius of the dopant cation. The ionic radii and atomic mass of rare earth dopants appear to be essential factors in the grain growth of the prepared compositions. The grain growth results in better crystallinity of the sample by reducing the microstrain with the increase of dopant ionic radius. Field emission scanning electron microscopy and energy-dispersive X-ray spectra confirm the prepared compositions' phase purity and stoichiometry. The UV–Vis spectra reveal that La-doped NBT composition exhibits the lowest optical band gap, which unfolds the application of NBT-based perovskite as photoactive material. The ac conductivity and complex impedance spectra unveil that the composition with the largest ionic radius, i.e., La-doped NBT compound, exhibits the highest dc and bulk conductivity with the lowest activation energy. The frequency-dependent dielectric data follows Havriliak–Negami (HN) formalism and non-Debye type relaxation phenomena. Results also indicate that La-doped NBT composition exhibits the highest dielectric strength value. Thus, this study first elaborates that the increasing ionic radius of the rare earth dopant cation in the Bi-site of NBT perovskite improves its microstructural, optical, and electrical properties.

Plasticization effect of ionic liquid on structural, thermal and ion transport properties of CS-PVA-NaI based bio-polymer electrolyte membranes

ABSTRACT Plasticized bio-polymer blend electrolytes (BPBEs) based on CS-PVA-NaI-xwt% ionic liquid (IL), 1-ethyl-3-methylimidazolium methyl sulfate [EMIM][MS] were prepared using solution cast method. The prepared samples have been characterized using FTIR (in ATR mode), XRD, TGA, Impedance spectroscopy, ITN, LSV, and CV measurement. XRD result shows the semi-crystalline nature of BPEs films with characteristic peaks centered at 2θ = 21°. The % degree of crystallinity (Xc) for BPBE films were found to decrease up to 15 wt%IL. FTIR analysis shows the interaction of NaI/IL with the constituents of polymer CS/PVA. Thermo-gravimetric analysis (TGA) shows that the BPBE film has multistep decomposition. AC conductivity spectra follow the Joncher’s power law (JPL) with the value of power law exponent >1. The transportation of charge carriers in the BPBE films follows the cage type correlate barrier hoping (CBH) mechanism. The sample, BPBE#15IL, was found to be optimum dc conductivity ~ 1.7x10−4S/cm at 30℃. The electrode polarization and conductivity relaxation in terms of dielectric permittivity and electric modulus have been realized. Ionic transference number (ITN) measurement reveals that the sample BPBE#15IL has the ionic conductivity due to ions only (ITN~ 0.99). LSV measurement shows that the value of electrochemical stability window (ESW) for sample BPBE#15IL ~±2.3 V. CV plot shows the appearance of symmetric oxidation-reduction peaks appeared at ~±1.5 V.

Structural and dielectric properties of Sr1-xCexMgyFe2-yO4 nano ferrites synthesized by citrate gel auto combustion method

A series of Sr1-xCexMgyFe2-yO4 (where x = y = 0.0, 0.25, 0.50, 0.75, and 1.0) nanoferrites were synthesised via the citrate gel auto combustion method. The synthesised materials structural and electrical properties were examined. Structural properties are investigated by x-ray diffraction analysis (XRD), SEM, and FTIR spectroscopy. X-ray diffraction analysis confirms the cubic spinel structure of the material. The crystalline size of the sample varied from 22 to 32 nm, whereas the lattice parameter was found to be 7.832 to 8.558 Ao. The lattice parameter's linear variation was not observed, which indicates that it does not obey Vegard's law. SEM images reveal those morphological characteristics, which are spherical shapes. EDAX confirms the presence of Sr, Ce, Mg, Fe, and O in the synthesised samples. FTIR spectra confirm the spinel structure with two sublattices, namely, tetrahedral and octahedral sites. Electrical properties carried out by LCR meter at different frequencies and dielectric parameters such as dielectric constant, dielectric loss, AC conductivity, and impedance spectra have been studied. Dielectric constant and loss decreased with increasing frequency, whereas AC conductivity increased. It was explained by the Maxwell-Wagner polarisation theory. A single semicircle type of behaviour was observed in Cole-Cole plots.

Mechanism of Polaronic Conduction in Olivine Phosphates: An Influence of Crystallite Size

We report the polaronic conduction mechanism in transition-metal phosphate with different crystallite sizes by performing broadband ac conductivity measurements. The conductivity spectra exhibited a frequency-independent dc conductivity at low frequencies, and the conductivity becomes frequency-dependent above the characteristic frequency. The temperature-dependent dc conductivity has been analyzed within the framework of Mott’s model of polaronic conduction, which exhibits non-Arrhenius behavior within the hopping conduction region. The apparent non-Arrhenius behavior is divided into three different regions depending on the type of lattice phonons associated with the bound charge carrier. Interestingly, at high temperatures, the dc conductivity is primarily determined by the polaron concentration, and it varies with temperature. To ascertain the temperature-dependent polaron concentration variation at high temperatures, the frequency-dependent conductivity spectra have been analyzed by scaling procedure individually on three distinct regions. The application of the Summerfield scaling law on the ac conductivity spectra at low- and intermediate-temperature regions follows the time–temperature superposition principle (TTSP). On the other hand, at high temperatures, the scaling of the ac conductivity spectra with the Summerfield scaling law was found to exhibit pronounced deviations. The scaling of the ac conductivity spectra at high temperatures was improved significantly using the random barrier model. We suggest that at high temperatures, the number density of polarons performing a long-range hopping process becomes a temperature-dependent quantity and increases with temperature.