Cole-Cole Plots Research Articles

Dielectric characteristics, dipolar relaxation dynamics and ac conductivity of CuO added lithium sulpho-phosphate glass system

In this work we have investigated the influence of copper ions on dielectric characteristics and ac conductivity of lithium sulpho magnesium phosphate glasses. Glass samples were synthesized by melt-quenching and annealing methods. The structural analysis of the glasses is performed by XPS, optical absorption (OA) and IR spectral studies. The XPS and OA spectral studies have revealed increasing fraction of Cu+ ions in the glasses, whereas IR spectral results indicated a growing degree of internal augmentation between various structural units the glass network with increase of CuO content. The dielectric parameters and a.c. conductivity, σac, exhibited decreasing trend while electrical impedance showed an increasing trend with increase of CuO concentration. The dipolar effects exhibited by electrical moduli dispersion spectra were analyzed by Cole-Cole plots. The increased degree of rigidity of the glass network is predicted to be responsible for the observed decrease of σac. The overall analysis of the variation of σac with CuO content indicated a gradual increment in the polaronic component at the expense of ionic component of conductivity. Finally, it is concluded that the studied glass doped with a small concentration of CuO is as useful as electrolyte material in solid-state batteries, whereas higher concentration of CuO is detrimental for such applications.

Low temperature synthesis and effect of Co doping on structural, optical and dielectric properties of CuCrO2 hexagonal nanoplates

In this research work, delafossite oxide CuCrO2 and its different Co doped compositions CuCr1-xCoxO2 (x = 0.05, 0.1, 0.15) were successfully synthesized by low temperature hydrothermal method. X-ray diffraction (XRD) confirmed the formation of CuCrO2 nanostructures with hexagonal structure having crystallite size less than 100 nm. The XRD peaks also confirmed that the fraction of Cr ions are perfectly replaced by the Co ions in the lattice structure. The crystallite size was found to decrease with increasing the doping concentration. The formation of nanoplates with hexagonal morphology was studied by using scanning electron microscope (SEM). The Fourier transform infrared spectroscopy (FTIR) was employed to analyze the occurrence of various functional groups, stretching and vibrational modes. Tauc's relation was used to calculate the optical band gap (Eg) of the samples from the absorbance spectra. Eg was observed to increase from 3.61eV to 3.95 eV which may be attributed to the reduction in crystallite size as a result of Co doping. The doping concentration also increases the density of grain boundaries which in turn induced the lattice strain in the crystal structure. The interplanar spacing d was observed to increase from 2.489 Å to 2.508 Å resulted due to induced strain. A maximum strain of 0.0132 was found in CuCr0.85Co0.15O2. The impedance and dielectric dispersion of the material were measured using LCR meter. The Cole-Cole plots represent the perfect dielectric behaviour of these materials indicating the pre dominant grain boundary resistance. The dielectric constant showed the increasing behaviour with Co doping concentration. Our results show that manipulation of the band gap and dielectric properties of CuCrO2 nanoplates with doping of Co ions can broadly enhance the efficiency and the applications of these oxide materials.

Influences of Ti4+ ion on dielectric property in perovskite structure of La ferrite (LaFe1-XTiXO3)

abstract The transition metals Ti-doped LaFeO3 is prepared by Microwave sintered techniques for different concentration (X = 0, 0.2, 0.4 and 0.6) the aqueous materials involved Lanthanum Nitrate, Ferric nitrate and used urea as a fuel additive. The synthesized sample LaFeO3 and LaFe1-XTiXO3 nanoparticle have been characterized by powder X-ray diffraction (XRD) analysis for the phase formation. Dielectric properties were represented in Dielectric constant, Dielectric loss, AC Conductivity, Impedance studies, Cole-Cole plots were analysed for the prepared nanoparticles for different frequencies at various temperatures. The dielectric properties as a purpose of frequency at low temperatures propose the occurrence of polarization in the samples owing to the electron hopping amid Fe3+ and Fe4+ ions.

Nanorods like microstructure, photocatalytic activity and ac-electrical properties of (1-x) (Al0.2La0.8TiO3) + (x) (BaTiO3) (x = 0.2, 0.4, 0.6 & 0.8) nanocomposites

Nanorods like (1-x) (Al0.2La0.8TiO3) + (x) (BaTiO3) (x = 0.2–0.8) composites were synthesized via hydrothermal technique. The XRD patterns indicated that tetragonal to cubic phase transformation was occurred from x = 0.4 to 0.6. The surface morphology revealed that the x = 0.2–0.8 exhibited the nanorods like structures. The photocatalytic activity was noticed for all nanocomposites during irradiation time from 0 to 150 min. In addition, the increasing spring model Cole-Cole plots were recorded for x = 0.2, 0.6 and 0.8 composites at high temperatures. The grain and grain boundary contribution in electrical conduction mechanism was described.

Electrochemical Study on Porous Silicon Anodes in Sulfide-Based All-Solid-State Lithium-Ion Batteries: II

All-solid-state lithium-ion battery (LIB) with high safety and reliability is the dominant power source for electric and hybrid vehicles. Here, to meet the energy demands of near-future automobile technology, the anode materials should possess high energy density and long cycle life. Though Si with a high theoretical capacity (4200 mAh g-1) is the most attractive choice, there are few applications for the all-solid-state LIBs. This is because the large volumetric fluctuation (>300%) in lithiation/delithiation causes the drastic capacity loss and low coulombic efficiency. Very recently, sulfide-based all-solid-state LIBs with porous Si composite anodes have exhibited high capacity retention [1]. We proposed the following mechanisms to consistently explain the experimental results [2]: (a) the volumetric expansion is buffered by the shrinkage of Si pores and (b) the stress arising from the Si particles is relieved by the elastic deformation of solid electrolyte (SE). In the present study, to provide further insight into these findings, the electrochemical characteristics were evaluated for the porous Si composite anodes with different SEs.Porous Si particles were prepared through air-oxidation demagnesiation of Mg2Si. The details have been described in our previous paper [1]. Anode composites were comprised of Si particles, SE, and acetylene black. Here Li3PS4 (LPS) and Li10GeP2S12 (LGPS) were adopted as sulfide-based SE. In an electric insulation tube, the anode composite and LPS powder were pressed to make two-layered pellet. As the counter electrode, Li-In foil was attached on the SE side. Finally, the three-layered pellet was compressed using stainless-steel disks. AC impedance of the half-cells thus prepared was measured in the range from 0.002 to 1 MHz.Figure 1 shows the cycle characteristics of LPS- and LPGS-cells. The LPS composite anode cell exhibited an initial discharge capacity of 1240 mAh g-1. On the other hand, a discharge capacity of 924 mAh g-1, which was about 30% lower than that of LPS-cell, was observed in the LGPS-cell. The maximum discharge capacity was 1532 mAh g-1 for LPS-cell and 1269 mAh g-1 for LGPS-cells, respectively. As the results, the capacity retention of LPS-cell was calculated as 95% at 50th cycle, compared to 83% in LGPS-cell. It is worthy to note that these values were extremely larger than those of non-porous Si anode cells. As shown in Cole-Cole plots, Figure 2, in the LPS composite anode cell, there was few changes in the arc size between 1st and 5th cycles. On the other hand, the arc of LPGS-cell became large with the increase of cycle number.The Young's modulus of LPS is known to be about 10% lower than that of LGPS [3]. Based on this fact, the above results are described as follows. Though the volumetric expansion is buffered by the shrinkage of pores, the porous Si particles slightly become large during lithiation. In LPS-cell, the stress should be relieved by the elasticity of surrounding SE. On the other hand, in LPGS with higher rigidity, voids are probably formed between the Si particles and the deformed SE, resulting in the lower capacity retention and higher interfacial resistance. In these considerations, we should note that LGPS with narrow potential window is prone to decompose in long cycles.

Dielectric Studies in Spherical Silica Nanoparticles doped Ferroelectric Liquid Crystal Mixture

in this paper, spherical silica nanoparticles were doped into a ferroelectric liquid crystal (FLC) material. Dielectric studies were carried out in the frequency range of 20Hz-1MHz. Temperature and frequency dependent dielectric permittivity were investigated in the undoped and doped samples. It was observed that adding a small amount of SNPs, the permittivity increases ∼20% than pure FLC mixture. A Goldstone mode was observed in both pristine FLC and SNPs doped FLC samples. The relaxation frequency of detected mode was also observed at ∼570 Hz and ∼715 Hz for pristine FLC and doped samples respectively at 34°C. A single relaxation behaviour was also described in the form of Cole-Cole plot.

Grain growth correlated complex impedance spectroscopy, modulus spectroscopy and carrier hopping mechanism in MnCo2O4: Influence of sintering temperature

This work primarily focuses on grain growth dependent electrical properties of spinel nano-cobaltite MnCo2O4 prepared by co-precipitation method and sintered at different temperatures between 400 and 1000 °C. XRD confirms formation of cubic manganese cobaltite. Rietveld method was used to estimate different microstructural parameters. Crystallite size increases with increasing sintering temperature from ~12.18 nm to ~97.95 nm which is comparable with grain growth noticed from FESEM micrographs. TGA-DSC curve shows long range phase stability of the materials. Cole-Cole plot obtained from complex impedance spectroscopy analysis shows non-Debye type depressed semi-circular nature. Activation energies evaluated from ac conductivity, migration energy and relaxation time approaches are consistent with each other indicating that the charge carriers have same barrier potential for conducting, migrating and relaxing. Hopping mechanism of charge carriers was confirmed from ac conductivity analysis. Conductivity is higher for sample sintered at higher temperature which might be associated with lowering of inter granular hopping distance. Master curves show good scaling behaviour of different spectra. It depicts that time-temperature superposition principle (TTSP) is valid for the samples and conduction mechanism is same at all temperatures.

Study on static and dynamic mechanical properties of hybrid palm stalk fiber reinforced epoxy composites

Static and dynamic effects of palm leaf stem stalk (PLSS) powder were investigated relative to the bi-directional palm stalk fiber reinforced epoxy composites. The PLSS bio-filler was incorporated into the epoxy resin by varying its content from 0 to 15 wt%. The hybrid palm-epoxy composites were manufactured using the hand-lay-up technique followed by light compression molding. The results for the mechanical properties of the PLSS particle (15 wt%)/palm/epoxy composites indicated an improvement in the tensile modulus, flexural modulus, and impact strength by approximately 33, 32, and 21%, respectively, when compared to the palm/epoxy composite. The dynamic mechanical analysis (DMA) of the composites showed an enhancement in the storage modulus, loss modulus and damping capacity (tan ) by approximately 75, 95, and 47%, respectively, when compared to the palm/epoxy composite. The fiber-matrix interaction was studied using a Cole-Cole plot analysis. The swelling and degradation resistance of the composites was increased with filler addition.

A study of filler content influence on dynamic mechanical and thermal characteristics of coir and luffa cylindrica reinforced hybrid composites

Natural fiber reinforced composites have occupied more applications in major engineering fields due to their improved mechanical properties and eco-friendly nature. In this work, the consequences of calcium carbonate (CaCO3) as filler on thermo-gravimetric (TG) and Dynamic Mechanical (DM) properties with various proportions along with coir/luffa cylindrical (C/L/C) hybrid epoxy composites were investigated. Different proportions of the CaCO3 (0, 2 and 4%) – C/L/C hybrid composite samples were fabricated using hand layup technique. TG and DM analysis were carried out on the fabricated composite specimens and the results like thermal stability, storage modulus, loss modulus and loss factor (Tanδ) of the composite specimens were evaluated and compared with filler less composite specimens. It was observed that 2 g of CaCO3-C/L/C hybrid composites have high thermal and dynamic mechanical characteristics as compared to the other composite samples. Moreover, Cole-Cole plot revealed excellent bonding among the fibre, filler and matrix. Based on the obtained results, it can be concluded that the composites with 2 g filler content can be used in major engineering applications due to their improved dynamic mechanical properties.

Dynamic-mechanical properties as a function of luffa fibre content and adhesion in a polyester composite

In this work, the characteristics of a vegetable fibre (luffa cylindrica) polyester composite are studied as a function of fibre surface treatment (with NaOH, Ca(OH)2 and silane) and fibre content (30%, 40% and 50%). Composites were prepared through compression moulding and characterized with thermogravimetric and dynamic-mechanical analyses. Higher storage modulus was obtained with Ca(OH)2 treated composites, reaching nearly 70% increase. Higher loss modulus (E”) was noted in for silane treated fibre (at 50%) and a high peak in damping factor was noted for Ca(OH)2 treated fibre (at 50%). Cole-cole plot showed highest homogeneity for the Ca(OH)2 treated composites. Electron microscopy revealed the fracture modes in static tested composites. The general properties obtained indicate that the composites can only be used for low loading applications.

Influence of TeO2 on the UV, electrical and structural studies of Li2O–ZnO– B2O3 glasses

Glass system of chemical composition xTeO2-(30-x)Li2O–20ZnO–50B2O3 with x = 0, 5, 10,15 and 20 mol% was fabricated through melt quench technique and investigated by X-ray diffraction technique, UV-Absorption spectroscopy, AC conductivity studies, FT-IR and Raman spectroscopy. No crystalline peaks were found in the XRD spectra which confirmed the amorphous nature of the glassy samples. The effect of conditional glass former TeO2 on the physical parameters like density, oxygen packing density (OPD) and molar volume have been investigated. The density of the glass system increased from 2.88 g/cm3 to 3.46 g/cm3 with the increase of TeO2 content. Optical absorption spectroscopic studies were carried out on the glass system. The Cut-off wave length (λc) varied between 300 nm and 370 nm whereas, the optical band gaps (Eopt) decreased with the addition of TeO2 in the glass network. The Urbach energy (ΔE) and refractive index of the glass system also increased. The AC conductivity measurements were studied up to high frequency (35 MHz) at various temperatures and conductivity observed in the higher order (10−2 Ω−1cm−1). Cole-Cole impedance plots shown semicircle behaviour in which the radius of semicircle decreased with increasing the temperature. Mechanical properties of the glass system were calculated using Makishima-Mackenzie model and the Poisson’s ratio values (0.17–0.21) are suggesting that the glass network has high cross link density. The Fourier Transform Infrared (FT-IR) and Raman spectroscopic studies revealed that the glass consisted of BO3 and BO4 units along with TeO3, TeO4 units.

Fluorescence and dielectric spectroscopy identification of polyvinyl chloride/NiO nanocomposites

Fluorescence spectra of the polyvinyl chloride (PVC)/NiO nanocomposites examined after excitation with wavelength of 340 nm. It revealed a visible emission peak shifted to longer wavelengths from 401.5 to 429.5 nm with the addition of 0.3 wt% of NiO nanoparticles. The dielectric properties of PVC/NiO nanocomposites also studied by broadband dielectric spectroscopy (BDS) as a function frequency (0.1 Hz - 20 MHz) at temperatures (303 – 383 K). The dielectric constant (έ) and dielectric loss (ε′′) increased with temperature but decreased with frequency. Dielectric loss peak detected at low frequency side associated with the glass-rubbery transition (α−relaxation) which shifted to higher frequencies upon increasing the temperature. The symmetric broadening shape parameter (α), average relaxation time (τo) and molecular relaxation time (τm) are calculated via the values of static (εo) and infinite (ε∞) dielectric constant estimated from Cole-Cole plots. AC conductivity followed the universal power law and enhanced with increasing both temperature and frequency owing to charge carriers hopping from one site to the others. The exponent (s) values are found to increase (0.63 – 0.9) with decreasing temperature which related to the (CBH) model. The maximum barrier height also exhibited enhancement from 0.025 to 0.027 eV with increasing the concentration of NiO, but decreased with increasing temperature.

Lead-Free BNT–BT0.08/CoFe2O4 Core–Shell Nanostructures with Potential Multifunctional Applications

Herein we report on novel multiferroic core–shell nanostructures of cobalt ferrite (CoFe2O4)–bismuth, sodium titanate doped with barium titanate (BNT–BT0.08), prepared by a two–step wet chemical procedure, using the sol–gel technique. The fraction of CoFe2O4 was varied from 1:0.5 to 1:1.5 = BNT–BT0.08/CoFe2O4 (molar ratio). X–ray diffraction confirmed the presence of both the spinel CoFe2O4 and the perovskite Bi0.5Na0.5TiO3 phases. Scanning electron microscopy analysis indicated that the diameter of the core–shell nanoparticles was between 15 and 40 nm. Transmission electron microscopy data showed two–phase composite nanostructures consisting of a BNT–BT0.08 core surrounded by a CoFe2O4 shell with an average thickness of 4–7 nm. Cole-Cole plots reveal the presence of grains and grain boundary effects in the BNT–BT0.08/CoFe2O4 composite. Moreover, the values of the dc conductivity were found to increase with the amount of CoFe2O4 semiconductive phase. Both X-ray photoelectron spectroscopy (XPS) and Mössbauer measurements have shown no change in the valence of the Fe3+, Co2+, Bi3+ and Ti4+ cations. This study provides a detailed insight into the magnetoelectric coupling of the multiferroic BNT–BT0.08/CoFe2O4 core–shell composite potentially suitable for magnetoelectric applications.

Correlative exploration of structural and dielectric properties with Er2O3 addition in BaO–ZnO–LiF–B2O3 glasses

Structural properties of a novel family of glasses 10BaO–20ZnO–20LiF-(50-x) B2O3-xEr2O3 where x = 0, 0.1, 0.5, 0.7 and 1.0 mol% were analysed through physical parameters, X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). Successive Er2O3 doping led to an increase in the glass density, refractive index, molar electronic polarizability and field strength around Er3+ ions. Absence of sharp peaks in the XRD profiles confirmed the amorphous nature. Increase in the number of [BO3] and Non-Bridging Oxygens through FTIR analysis and decrease in the glass transition temperature (Tg) with successive Er2O3 addition validated the structural modification in the network which was then correlated with the dielectric properties of the glasses, evaluated through broadband impedance spectroscopy. Variation of dielectric parameters like dielectric constant, loss, loss tangent, quality factor, modulus, capacitance, conductivity was recorded in 323–673 K and 1 Hz-1 MHz range. An improvement in the dielectric constant was found with the successive addition of Er2O3. High quality factor was observed at 323–523 K and 1 kHz to 1 MHz. ac- (σac) and dc- (σdc) components of electrical conductivity were identified by Jonscher’s universal power law. Using Arrhenius relation, high activation energies (>1 eV) were obtained for all the glasses. Cole-Cole plot attributed the relaxation to non-Debye type. From the decreasing values of frequency component (s) in the Jonscher’s universal power law with increasing temperature, the conductivity mechanism in the glasses was assigned to Correlated Barrier Hopping model.

Crystal structure refinement, optical properties, dielectric response, and impedance spectroscopy of Ni2+-Co2+ substituted bismuth copper titanate (BCTO)

We have synthesized single phase Ni+2-Co+2 substituted bismuth copper titanate (Bi2/3Cu3Ti4O12) electroceramic using the sol-gel autocombustion method. The XRD patterns reveal that the prepared BCTO electroceramic are of single phase without the presence of any other phases such as CuO or TiO2. FESEM micrographs show particles with well-defined cubic shape of bismuth copper titanate ceramics. EDX spectra shows all the chemical elements of the prepared composition, this confirm the stoichiometry and the purity of the synthesized electroceramic. The optical band gap study was carried out using UV–Vis–NIR spectroscopy in the region 225–1000 nm and the highest value of 3.63 eV was observed in the sample having x = 0.1. The dielectric response and impedance spectroscopy of the electroceramic were discussed based on Debye-type relaxation process and Maxwell-Wagner model. The sample having x = 0.0 shows the highest dielectric constant (3800) at room-temperature and a frequency of 42 Hz as compared to x = 0.1 and x = 0.2. The Cole-Cole plots of complex impedance and complex electric modulus indicate that grain-boundary resistance is the major contributor to the dielectric response of the prepared BCTO electroceramic.

Improving electrical properties of ZnO–Bi2O3–Sb2O3–MnO2 varistors by doping with pre-synthesized Bi–Si–O phase

Abstract The electric properties and microstructure of ZnO -Bi2O3– Sb2O3– MnO2 (ZBSM) varistor ceramics as a function of pre-synthesized mixture of 6Bi2O3 SiO2 (Bi–Si–O) were investigated. The introduction of Bi–Si–O increases liquid phase content during the sintering process, accelerating the solid solubility of MnO2, Sb2O3 and possibly partial Si ions towards ZnO grains. As results, the interface state density significantly increases to 16.43 × 1016/m2 in the 4 wt% Bi–Si–O ZBSM ceramic, which leads to the highest value of barrier height of 5.87 eV and nonlinear coefficient of 54.56. At the same time, the electric breakdown voltage and leakage current density decreases to 613.82 V/mm and 0.001 μA mm−2, respectively. Besides, grain boundary resistance gradually increases with increasing Bi–Si–O dopant (x ≤ 4 wt%) and then decreases sharply to a very low value when x = 6 wt%, which consists with the variation of leakage current density. Furthermore, only one relaxation occurred in ZBSM-xBi-Si-O varistors which can be confirmed by the Cole-Cole plot analysis. Oxygen absorption and ion migration mechanisms are used to explain the enhancement of nonlinear electrical properties.

Enhanced electrical properties of ZnO varistor ceramics by spark plasma sintering: Role of annealing

ZnO varistor ceramics are synthesized by spark plasma sintering (SPS), and then annealed in a conventional furnace in air atmosphere. Dense microstructure with more than 98% of theoretical density is achieved, and homogenous ZnO grains with typical second phases such as Zn7Sb2O12 spinel, Zn2Bi3Sb3O14 pyrochlore are observed from X-ray diffraction spectra (XRD) and scanning electron microscopy (SEM). In addition, a metallic Bi phase is also observed, which is resulted from the reduction of Bi2O3 because of inherent low oxygen partial pressure of SPS, and it can be reoxidized after a post-annealing process. The breakdown field of the optimum ZnO varistor ceramic is 725 V/mm with a nonlinear coefficient of 53.5, which stems from its high Schottky barrier height of 0.60 eV. In analysis of dielectric spectra from 173 K to 293 K, two relaxation peaks with activation energy of 0.22 eV and 0.48–0.54 eV can be observed, which are attributed to the intrinsic zinc interstitial and defect of grain boundary or intergranular phase, respectively. The grain boundary resistances are discussed according to Cole-Cole plot, from which the activation energy controlling resistance at the grain boundary is determined to be 0.87 eV.

Defect dipole polarization mechanism in low-dimensional europium substituted Al0.8La0.2TiO3 nanostructures

Abstract Low-dimensional Europium substituted Al0.8La0.2TiO3 (Al0.8EuyLa0.2-yTiO3 (y = 0.01–0.04))/AELTO nanostructures were prepared via hydrothermal method. The X-ray diffraction (XRD) patterns revealed the mixed phase (tetragonal and orthorhombic) structure of AELTO. Furthermore, the surface morphology evidenced the formation of AELTO nanostructures. The wide optical band gap (Eg) was achieved for y = 0.01–0.04 contents and found to be varying from 3.371 to 3.399 eV. The high dielectric constant (e′) values of 2.84 × 108 at 10 kHz and 101608.8 at 1 MHz were obtained for y = 0.02 at room temperature due to defect dipoles. In addition, the high ac-electrical conductivity (σac) of 15.78 S/cm (at 10 kHz) was observed at room temperature. The frequency dependence of dielectric modulus and impedance parameters was elucidated. The reverse arc present in the Cole-Cole plot of y = 0.02 content clearly suggested the presence of defect dipoles in AELTO.

A study of dielectric relaxation properties of ZnFe2-xBixO4 nano Ferrites synthesized by sol-gel combustion method

A series of bismuth doped zinc nano ferrite particles with the r formula ZnBixFe2-xO4 (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method; and these compositions were sintered at 600°C for 5 hrs. With the effect of bismuth doping, the structural properties of all prepared samples were characterized by X-ray diffraction (XRD). The X-ray diffraction spectra analyses confirm single phase cubic (FCC) spinal structure. The average crystallite size (D) of the samples found to be in the range 17-20 nm. The dielectric properties viz., dielectric constant (ε′), dielectric loss tangent (tan δ) and AC conductivity σAC) were measured at room temperature in the range 20Hz to 2MHz, which confirm the normal ferrite behavior. In the present research work, we are intended to extend dielectric relaxation studies of these samples with the help of Cole-Cole plots. The Cole-Cole plots of the bismuth doped zinc ferrites were drawn as a function of ε′ and ε″ (where, ε″=ε′ tan δ) and hence we have determined the spreading factor (β) for all the samples. It was observed that β decreases with the increase of the concentration of B2O3. It is noticed that the dielectric parameters ε′, tan δ and σAC have exhibited the similar trend. These samples may find suitable applications in electrolytic elements in battery technology.

Dip-coated V doped ZnO thin films: Dielectric and magnetic properties

Thin film materials are getting the attention of the researchers because of the growing demand of the electronic industry. This demand is not only due to the low-cost method of preparation but also due to tuneable room temperature dielectric and magnetic properties. The thin films of V-doped ZnO were studied for their dielectric and magnetic properties at room temperature. Impedance analyser and vibrating sample magnetometer were used respectively.for dielectric and magnetic measurements. The thin films were previously prepared by changing the doping percentage of 0, 1, 3, 5, 7, 9 at. wt % of vanadium, using dip coated sol-gel route. These thin films exhibit normal behavior of dielectric constant. Dielectric constant increased to 35.64 (at 1MHz) with the increase in V doping to 9 at. wt % in ZnO. The loss tangent decreases to 0.00182 (at 1MHz) and AC conductivity increases to 2.46x10-9 Sm/m (at 1MHz) with increasing frequency. The cole-cole plot exhibits one semicircle arc due to high grain boundary resistance. The thin films of V doped ZnO show room temperature paramagnetism to ferromagnetism transition. The saturation magnetization increases with the increase in vanadium contents and reached to the maximum value of 50.56 emu/cm3.