Jonscher's Universal Power Law Research Articles

Synthesis and characterization of Ruddlesden-Popper system (Ba1−xSrx)2SnO4

The samples of (Ba1−xSrx)2SnO4 with x = 0, 0.10, 0.20, 0.40, 0.80, 1.00 were synthesized by a high-temperature solid state ceramic route. Lattice parameters obtained from the Rietveld profile analysis; decreased with increasing Sr. The decreasing nature of lattice parameters indicated the complete solubility of Sr at Ba-site. Further, incorporation of Sr at Ba-site has been studied by Fourier transform infrared (FTIR) spectroscopy. The dielectric constant and dissipation factor increases with increasing Sr. Contribution of grain and grain boundary were resolved by complex modulus spectroscopy analysis. AC conductivity spectra of the entire sample follow Universal Jonscher's power law. The similar value of activation energy obtained from relaxation frequency and dc conductivity implies that the origin of conduction and relaxation mechanisms remains the same throughout the samples. The modulus and conductivity spectra of solid solutions nicely follow the time-temperature superposition (TTSP) principle. Further, conductivity spectra of solid solutions were studied by Ghosh and Summerfield scaling.

Investigation of electrical properties and conduction mechanism using CBH model of Ba0.97La0.02Ti1−xNb4x/5O3 (x = 0.00 and 0.02) compounds

Lead-free Ba0.97La0.02Ti1−xNb4x/5O3 (abbreviated as BLT and BLT0.98Nb0.016) ceramics were grown using the molten-salt method with filtration as well as evaporation technique. A correlation investigation between the morphological, structural, and electrical properties of the system was carried out using impedance spectroscopy at various frequencies (40–106 Hz) and temperatures (500–600 K). In the present work, average grain size estimated from the microstructure was ~ 2700 nm. Phase composition was established by the Rietveld refinement, which confirms that our compounds have a single phased nature and crystal structure. They have a tetragonal Perovskite structure with a P4/mmm space group, without any secondary phases. Z′ and Z″ values of impedance decreased with increasing Nb concentration. The EIS data displayed an approximately perfect semi-circle at high temperature in the complex plane plot as well as a practically ideal non-Debye peak shape in the spectroscopic plot. The electrical conductivity decreased with increasing niobium amount. The frequency dependence of conductivity plot has been found to obey the universal Jonscher power law. The correlated barrier hoping was established to be the most suitable theoretical model to elucidate the conduction process. These results could help improve the electrical properties of Ba0.97La0.02Ti1−xNb4x/5O3 compounds and understand the relationship between the structure and the electrical properties.

Role of Multiferroic Filler on the AC Response of Bi1‐xBaxFeO3 doped PVA:NH4CH3COO Nanocomposite Gel Polymer Electrolytes

AbstractThe frequency dependent AC conductivity and dielectric studies of multiferroic filler (Bi1‐xBaxFeO3) doped nanocomposite gel polymer electrolyte (NCGPEs) based on PVA:(NH4CH3COO) are investigated in the present work. The nano composite gel polymer electrolyte systems are synthesized for various filler concentrations by solution cast method. The effect of filler concentration on ionic conductivity is studied using AC impedance technique in the frequency range 1–106 Hz. X‐ray diffraction studies reveal the formation of nanocomposite gel polymer electrolyte. The low frequency dispersion in the dielectric response of electrolytes shows the relaxation contribution is superimposed with electrode polarization effects. The relaxation peaks in the NCGPEs are found to shift toward higher frequency side with increasing filler concentration and are suitably correlated to change in morphology of the gel electrolyte system. The variation of AC conductivity with frequency is seen to obey Jonscher's universal power law with the exception of small deviation in the low frequency regime. Modulus formalism of dielectric response suggests that the ion transport is strongly coupled to the polymer segmental motion.

Dielectric Modulus and Conductivity Scaling Approach to the Analysis of Ion Transport in Solid Polymer Electrolytes

Solid polymer electrolyte films (SPEs) based on poly(methyl methacrylate) are prepared using a solution cast technique. The temperature‐dependent behavior of dielectric, modulus spectra and ac conductivity has been investigated. The long tail of the real part of modulus (M′) in the low frequency indicates the capacitive nature of the samples. The frequency dependence of imaginary part of modulus (M″) shows a non‐Debye relaxation that has been explained using the Kohlrausch–Williams–Watts stretched exponential function. The activation energy for the relaxation is almost same as the activation energy for the conduction. The relaxation time obtained from the tangent loss graph (τδ) is about two orders of magnitude larger than that obtained from the imaginary part of modulus graph (τm). The ac conductivity has been found to obey Jonscher's universal power law. Transport parameters show that addition of filler creates additional hopping sites for the charge carriers and also increases the charge carrier density. It is also observed that the higher ionic conductivity at higher temperature is due to increased thermally activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from Summerfield scaling. POLYM. ENG. SCI., 60: 297–305, 2019. © 2019 Society of Plastics Engineers

Studies on structural and electrical behaviors of chemically grown ZnO/SnO2 nanocomposites

Nanostructured oxides are attracting enormous interest due to their variety of applications such as energy materials, dielectrics, ferroelectrics, piezoelectrics, superconductors, spintronics, catalysts, biological agents, etc. For the present study, ZnO:SnO2 nanocomposites were prepared by addition of nanostructured SnO2 in ZnO nanostructured matrix. X–ray diffraction (XRD) measurement reveals the single phase nature of pure ZnO and SnO2 oxides as well as their composites. Variation in a.c. conductivity has been discussed on the basis of Jonscher's universal power law which suggests that charge conduction is governed by correlated barrier hopping (CBH) mechanism. Estimated maximum barrier height is found to decrease with increase in SnO2 nanoparticles content in the nanostructured ZnO matrix. Dielectric behavior has been understood in the context of relaxation formula and universal dielectric relaxation (UDR) model. Relaxation fits suggest that SnO2 content suppresses the relaxation time for dipoles to get aligned whereas it enhances the relaxation time distribution factor.

Structural, optical, and dielectric properties of LaFe1−xMnxO3 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) perovskites

Herein, we investigated the structural, optical, and dielectric properties of perovskite LaFe1−xMnxO3 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) polycrystalline ceramics synthesized using sol–gel and sintering methods. X-ray diffraction measurements revealed that these materials adopt a single-phase orthorhombic crystal structure (space group Pnma). The effects of the Mn substitution induce changes in the lattice parameters including the Fe/Mn–O–Fe/Mn bond angle, Fe/Mn–O bond length, and tilting of the bond angle; these changes are also supported by the tolerance factor calculations and Raman scattering analysis. The complex impedance of the samples was measured in the temperature range of 100 °C to 275 °C and over the frequency range of 100 Hz to 1 MHz. The Nyquist plots, i.e., Z″ versus Z′ over the entire frequency range, resembled semicircular arcs and could be described by an electrical equivalent circuit model. The complex conductivity of the samples was investigated using both the equivalent circuit modelling and the Jonscher universal power law. The activation energies of the conduction processes obtained from both methods were very similar, indicating that the model comprising discrete electrical components used to interpret the response of the real system is applicable. The activation energies from conduction and relaxation processes were found to be < 1 eV, indicating that the mechanisms might be predominantly induced by oxygen ionic conductivity rather than electronic conductivity and oxygen vacancies.

Grain size effect on the electrical properties of nanocrystalline Gd2Zr2O7 ceramics

A detailed study on the effect of grain size of nanocrystalline Gd2Zr2O7 (GZO) ceramics on its electrical properties, particularly the ionic conductivity, is reported. The nanocrystalline GZO was prepared by chemical co-precipitation method. The GZO ceramic with different grain sizes from 5 to 55 nm was fabricated by sintering them at different temperatures varying from 800 to 1400 °C. Structural studies were performed by X-ray diffraction and Raman spectroscopy and found the cubic pyrochlore phase of GZO in all cases. Their crystallite size has been increased from 5 to 55 nm as well as the structural ordering has been increased with the increase in sintering temperature. The ac electrical impedance analysis showed a dramatic increase in ionic conductivity with increasing grain size. The ionic conductivity measured at 700 °C was 8.7 × 10−6, 12.5 × 10−6, 20.4 × 10−6 and 45.4 × 10−6 S cm−1 for respective grain sizes 5, 12, 25, and 55 nm of GZO ceramics. Increase in conductivity was correlated to the increase in grain size. The activation energy for grain conductivity was found to be 1.42 ± 0.01 eV for all GZO ceramics irrespective of their grain size. However, the activation energy of grain boundary and total conductivity had decreased with increasing grain size. The activation energy for total conductivity was obtained to be 1.5, 1.48, 1.46 and 1.42 eV for 5, 12, 25, and 55 nm GZO ceramics respectively. Further, the ac conductivity was found to obey the universal Jonscher's power law and the power exponent s was found to increase with the increase in temperature. It was also showed that the non-overlapping small polaron tunneling (NSPT) has been the best suited theoretical model to explain the conduction mechanism occurred in GZO ceramics. In addition, increase in co-operative dynamics of mobile ions with increase in grain size was found to favor the enhancement of conductivity.

Broad range frequency – temperature response of Ba2Zn2Fe12O22

Ba2Zn2Fe12O22 was synthesized by solid state reaction technique. The temperature and frequency dependent electrical properties and complex impedance spectroscopy were analysed. Complex modulus formalism shows the existence of high resistance and small capacitance of the material for the short range relaxation. The presence of non-Debye type relaxation is revealed from Nyquist plots and enabled to separate the contribution from bulk and grain boundary effect in the material. Further, the ac electrical conductivity of the material was well agreed with the Jonscher's universal power law.

Synthesis, characterization, DFT calculations, electric and dielectric properties of (C6H10(NH3)2) CdCl4 H2O organic-inorganic hybrid compound

Single crystals of a new organic-inorganic material (C6H10(NH3)2) CdCl4·H2O, were grown through a slow evaporation at room temperature and were characterized using X-ray diffraction, FT–IR, FT–Raman, UV–Vis and impedance spectroscopy analyses. This compound crystallizes in the monoclinic system (P21/c space group). The [CdCl4]2- anions form an infinite sheet of octahedrons and diprotonated (C6H10(NH3)2)2+ cations that are arranged in an opposite way. The crystal pattern is stabilized by 2D network via non-covalent N–H⋯Cl, N–H⋯O and O–H⋯Cl interactions. The density functional theory DFT was applied to investigate molecular structure and vibrational modes. The calculations were performed by using B3LYP functional method combined with LanL2DZ basis set. The optimized structure and the vibrational spectra are in good agreement with the experimental measurements. The topological atom-in-molecules (AIM) and the Hirshfeld Surface (HS) analyses were carried out to investigate quantitatively the intermolecular contacts in crystal packing in a visual manner. The optical properties were investigated by optical absorption explains the eventual charge transfer interactions that take place within the molecules. Finally the electrical and the dielectric properties of this compound were investigated by means of impedance spectroscopy measurements over a wide range of frequencies and temperatures, 209 Hz–5 MHz and 300–393 K, respectively. Nyquist plots reveal a non-Debye type relaxation process and confirmed that the complex impedance curves of the title compound obeyed the Cole–Cole formalism. Furthermore, The AC conductivity behavior of the compound has been analyzed by the Jonscher's universal power law.

Structural, magnetic and dielectric properties of Ni0.6Mg0.4Fe2O4 ferromagnetic ferrite prepared by sol gel method

Structural, magnetic, electrical and dielectric properties of Ni 0.6 Mg 0.4 Fe 2 O 4 ferromagnetic ferrite synthetized using sol gel method have been studied. XRD measurements confirm that the compound crystallizes in the cubic structure with F d 3 ¯ m space group. Magnetic properties of our sample are analyzed by the hysteresis loop, which shows a ferromagnetic character at room temperature. Electrical characterization is performed by measuring the conductance as a function of frequency ranging from 10 Hz to 5 MHz and under different temperatures 295–440 K. The conductance response is investigated in the basis of Jonscher universal power law: G(ω) = G DC + Aω n , where ω is the frequency, and n is the exponent. DC electrical region analysis indicates a semiconductor behavior in which the conductivity is governed by the small polaron hopping process. The determined activation energy is about 0.242 eV. The conduction mechanism is affected by the grain and grain boundaries contribution, which is confirmed by the modulus analysis. Finally, the dielectric permittivity and dielectric loss are measured. We found that the Ni 0.6 Mg 0.4 Fe 2 O 4 ferrites have a significate permittivity at room temperature and a very low dielectric loss. These results offer the possibility of nanoelectronics application using this high performance ferromagnetic ferrite.

Dielectric and optical properties of Ni- and Fe-doped CeO2 Nanoparticles

Ni- and Fe-doped CeO2 nanoparticles were prepared by a chemical co-precipitation method and then heat treated at 300 °C. The structural, morphological, and compositional properties of the prepared nanoparticles were studied by powder X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FT-IR) Spectroscopy. The powder XRD results revealed that all the samples exhibit the typical cubic fluorite structure of CeO2. The EDS and FTIR analyses confirmed the formation of CeO2 nanoparticles and the incorporation of Fe and Ni ions in the crystal lattice of CeO2. The photoluminescence (PL) properties were investigated to assess the effect of Fe- and Ni-doping on the emission properties of CeO2 nanoparticles. The impacts of the type of dopant on the dielectric properties and ac conductivity of the prepared nanoparticles were investigated. It was observed that the dielectric constant of Ni-doped CeO2 nanoparticles measured at low-frequency region is much greater than that of Fe-doped CeO2 nanoparticles. The difference was explained on the basis of interfacial/space charge polarization, with Ni-doped CeO2 nanoparticles having a more heterogeneous dielectric structure. The universal Jonscher power law was well adjusted to the ac conductivity spectra. It was shown that the Fe-CeO2 composite nanoparticles are less conductive than the Ni-doped CeO2 ones.

Structural characterization and electrical conductivity analysis of MoO3–SeO2–ZnO semiconducting glass nanocomposites

A series of glass nanocomposite samples of the general composition formula xMoO3–(1-x) (0.5SeO2–0.5ZnO) for x = 0.05, 0.1, 0.2, and 0.3 have been prepared by solid-state reaction, i.e., slow cooling process. The structural characteristics have been explored by analyzing X-ray diffraction patterns, Fourier-transform infrared, and UV–Vis spectra. The superposition of different nanophases SeO2, SeO3, ZnO, MoO3, Zn (SeO3), Zn (SeO4), Zn(MoO4), Zn2Mo3O8 and ZnMo8O10 over the amorphous glassy matrices have been identified, and their crystallite sizes have been evaluated as well. Fourier transform infrared (FTIR) spectra reveal different types of bonding like Zn–O–Se type and stretching vibrations of MoO6 octahedral units. It is observed that with increasing MoO3 concentration, the estimated values of optical bandgap energy, Urbach energy, and average crystallite size reduce. The dependency of electrical conductivity on frequency and temperature have been analyzed using Almond-West formalism and Jonscher's universal power-law. The non-linear character of DC conductivity and different activation energies at low and high-temperature regions affirm that the present glassy systems exhibit semiconducting nature. Moreover, DC conduction process is due to small polaron hopping through localized or defect states. The decreasing trend of power-law exponent (s) with temperature rise reveals that AC conduction mechanism is consistent with the correlated barrier-hopping (CBH) model. The existing correlated barrier-hopping model has been modified to attain reasonable values of fitting parameters and to obtain theoretical values of ideal thermodynamic glass transition temperature. The AC conductivity activation energy and free energy required for small polaron migration reduce with increasing conductivity. The scaling property emphasizes that conductivity relaxation process is subjected to the structure of the composition and does not depend on temperature.

An investigation of S–Se–Te semiconducting glassy alloys: Structural characterization and electrical conductivity

A sequence of chalcogenide glassy alloys, xS-(1-x) (0.5Te-0.5Se) for x = 0.1, 0.14, 0.24 and 0.34 have been prepared using well-established melt quenching method. The XRD patterns reveal the existence of crystallinity, superimposing over the amorphous glassy matrix. The effects of increasing values of mean crystallite size and optical band gap energy with composition cause electrical conductivity to reduce. The DC conductivities of the present system have been explored using Mott and Greaves's variable range hopping model. The values of temperature dependent small polaron hopping distance (Rhop) and hopping energy (Whop) are in agreement with the nature of DC conductivity. The anomaly of the sample for x = 0.14 may arise due to the lesser number of localized or defect states within the mobility gap and higher values of small polaron hopping distance and average hopping energy. The well-known Meyer-Neldel rule, Jonscher's Universal power-law and Almond-West formalism have been employed to investigate the AC conductivity spectra. The reducing nature of power-law exponent (s) with increasing temperature of the samples for x = 0.1 and 0.14 indicates that correlated barrier hopping (CBH) model is the best model for AC conduction mechanism. On the other hand, non-overlapping small polaron tunneling (NSPT) process is the suitable AC conduction mechanism of the samples for x = 0.24 and 0.34 due to the increasing nature of s with temperature. The conductivity scaling signifies temperature independency and composition dependency of electrical relaxation process.

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.

Na3Bi(AsO4)2: Synthesis, crystal structure and ionic conductivity

Single crystals of the new Bi(III) arsenate, Na3Bi(AsO4)2 have been isolated and their structure has been determined by X-ray diffraction. This compound crystallizes in the monoclinic space group P21/n with a = 5.5275 (2) Å; b = 19.271 (7) Å; c = 7.156 (3) Å, β = 92.104 (32)° and Z = 4. Na3Bi(AsO4)2 features a three-dimensional open anionic framework made up of corner-sharing BiO6 and AsO4 polyhedra. Its structure can be described as buckled infinite anionic layers parallel to (001) planes, connected via As–O–Bi bridges to form a three-dimensional open framework. This architecture gives rise to wide tunnels running along the [100] direction where the sodium ions are located. The ionic conductivity measurements are performed on pellets of 91% relative density. The highest overall conductivity of 1.3 × 10−5 S cm−1 was found at 500 °C with Ea = 0.76 eV. The value of the activation energy obtained from the analysis of the impedance spectra suggests the ionic transport in Na3Bi(AsO4)2 is essentially due to simple hopping of Na+ cations. Furthermore, the frequency dependence of AC conductivity was shown to obey the Jonscher universal power law.

Lithium ion conductivity in Li2O–P2O5–ZnO glass-ceramics

A series of new glass-ceramic samples containing Li2O has been prepared to explore their electrical transport properties. XRD patterns of them reveal the formation of different types of nanocrystallites, dispersed in amorphous glassy matrices. Study of dc conductivity (σdc) of them shows their thermally activated nature. Formation of more non-bridging oxygen in the compositions may enhance their ionic conductivity. Conductivity spectra at various temperatures have been studied and interpreted using Jonscher's universal power-law and Almond-West formalism to shed some light on transport mechanism. The frequency independent conductivity (plateau region) in low-frequency zone is caused by diffusion of Li+ ions. Moreover, in the high-frequency dispersive region, the conductivity is because of correlated and pseudo-three-dimensional motion of Li+ ions in percolating networks. In consequence, the power-law exponent values become greater than 1 and exhibit super-linear and/or NCL (nearly constant loss) nature. Correlated barrier hopping (CBH) model is modified to some extent, which yields a better fit to experimental results. Here, ion hopping and characteristic relaxation times have been correlated with electrical conductivity with good precision. The master curve in conductivity scaling analysis reveals that conductivity relaxation process in the present system are independent of temperature as well as composition.

Microstructural interpretation of charge transport dynamics of chemically derived ZnCo2O4 under mechanical milling

In this work, milling effect on chemically synthesized nanocrystalline Zinc Cobaltite (ZnCo2O4) has been investigated and we report how the structural and electrical properties vary with the milling span. Phase pure ZnCo2O4 has been successfully synthesized via simple and cost-effective co-precipitation method and then it has been milled for one, four and 8 h respectively. XRD confirms formation of single phase cubic structure for both milled and unmilled nano-powders. Different microstructural parameters has been estimated from Rietveld analysis, which shows particle size reduction from ∼29.64 nm for unmilled sample to ∼18.13 nm for 8 h milled sample. TGA-DSC curve of as prepared sample shows good temperature stability that helps to estimate the appropriate sintering temperature for the samples. TEM analysis also gives values of grain size in agreement with Reitveld analysis. Frequency dependent ac conductivity curve obeys universal Jonscher power law and temperature dependence of frequency exponent is explained by small polaron transaction. Comparable activation energies from hopping mechanism and relaxation process indicates similar transport mechanism. Superimposed scaling spectra obeys TTSP principle. AC conductivity increases with frequency as a result of hopping of the charge carriers. Smaller particles with reduced strain gives enhanced conductivity as well as enhanced value of hopping frequency. This further suggests creation of excess charge carriers in milled samples. Cole-Cole plot shows non-Debye type behaviour of the samples. The dielectric loss factor increases with lowering of particle size since smaller grains contributes to faster charge conduction.

Effect of Nb-doping on the structural and electrical properties of Ba0.97La0.02Ti1-xNb4x/5O3 ceramics at room temperature synthesized by molten-salt method

We, herein, report on the structural and electrical properties of Ba0,97La0.02Ti1-xNb4x/5O3 ceramics prepared by the molten-salt method. The XRD patterns of the samples at room temperature showed a single perovskite phase having a tetragonal structure with a P4/mmm space group. The electrical properties were studied by complex impedance spectroscopy in the frequency range (1–107Hz) at room temperature. The real and imaginary parts of impedance decreased with increasing Nb concentration. The complex impedance plot exhibited a single impedance semicircle for each compound, identified over the high and medium frequencies followed by a linear section, at low frequency, is explained by Warburg's element. The study of the normalization curves of impedance and electrical modulus showed a mismatch of both peaks, which suggests the presence of short-range motion of charge carriers. The electrical conductivity decreased with increasing niobium amount and the experimental data were fitted using Jonscher's universal power law. The exponent n is slightly superior to 1, indicating that the hopping occurs between neighboring sites.

Hydrogen-bonded and supramolecular ferroelectricity in a new hybrid (C12H25NH3)2CoCl4

A new organic-inorganic layered halide perovskite ((C12H25NH3)2CoCl4) has been synthesized and characterized by: chemical analysis, x-ray powder diffraction, differential scanning calorimetry, and differential thermal analysis thermographs. The dielectric and ferroelectric properties have been investigated. Analysis of the ac conductivity σac (ω, T) measured in the temperature interval from 110 K to 370 K and at selected frequencies in the range 1 kHz < f < 100 kHz and the results show that the Jonscher universal power law is accurately obeyed. The existence of ferroelectricity has been demonstrated by the hysteresis P-E loop. The collective data evidenced that the hybrid behaves as a proper ferroelectric rather than a relaxor one and undergoes an order-disorder ferroelectric phase transition at the Curie temperature Tc (Tc ≈ 360 K) accompanied with a structural distortion from an intercalated to non- intercalated state as the other Co and/or Zn hybrids. Since the room temperature space group of the hybrid is centrosymmetric (P21/c), the ferroelectricity should be due to the supramolecular interaction which results from the induced dipoles. The hydrogen bonding system of the type N–H….Cl plays the key role in the mechanism of supramolecular ferroelectricity.

Structural, electrical and dielectric studies of nano-composite polymer blend electrolyte films based on (70–x) PVA–x PVP–NaI–SiO2

Nano-composite polymer electrolytes (NCPEs) films based on PVA-PVP-NaI-SiO2 have been prepared using solution casting technique. Investigation of prepared films have been made using various experimental techniques like x-ray diffraction (XRD), attenuated total reflection–fourier transform infrared (ATR-FTIR), differential scanning calorimetric (DSC) and ac impedance spectroscopy. XRD determines the structural properties and shows the significant variation in the characteristic peaks related to semi-crystalline/amorphous phase of different PVA-PVP polymer blend ratio for fixed loading of NaI and SiO2. Complexation of PVA-PVP polymer blend with NaI and SiO2 has been confirmed by ATR–FTIR analysis. Variation in glass transition temperature (Tg) and melting temperature (Tm) of PVA-PVP-NaI-SiO2 NCPE system having various concentration of PVP were observed by DSC analysis. It has been observed that ac conductivity spectra strongly obeys the Jonscher's universal power law [σ=σdc+Afn] with power exponent, n < 1. The dielectric permittivity (ε′&ε″) and electric modulus (M′&M″) measurements were performed in a wide frequency range (10 mHz-10 MHz). Variation of conductivity with temperature shows that the ion conduction and polymer segmental motions are closely related and are governed by Arrhenius mechanism. A couple of peaks observed in loss tangent (tan δ) shows two types of relaxation processes interpreted in terms of dipole segmental motion (α-relaxation) and side chain dipole group motion (β-relaxation).