Dielectric Constant Decreases Research Articles

Structural, Magnetic, and Electrical Properties of CoFe2O4 Nanostructures Synthesized Using Microwave-Assisted Hydrothermal Method.

Magnetic nanostructures of CoFe2O4 were synthesized via a microwave-assisted hydrothermal route. The prepared nanostructures were investigated using X-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selective area electron diffraction (SAED) pattern, DC magnetization, and dielectric spectroscopy measurements. The crystal structure studied using HR-TEM, SAED, and XRD patterns revealed that the synthesized nanostructures had a single-phase nature and ruled out the possibility of any secondary phase. The lattice parameters and unit cell volume determined from the XRD data were found to be 8.4821 Å and 583.88 Å3. The average crystallite size (~7.0 nm) was determined using Scherrer's equation. The FE-SEM and TEM micrographs revealed that the prepared nanostructures had a spherical shape morphology. The EDX results showed that the major elements present in the samples were Co, Fe, and O. The magnetization (M) versus temperature (T) measurements specified that the CoFe2O4 nanostructures showed ferromagnetic ordering at room temperature. The blocking temperature (TB) determined using the M-T curve was found to be 315 K. The magnetic hysteresis (M-H) loop of the CoFe2O4 nanostructures recorded at different temperatures showed the ferromagnetic behavior of the CoFe2O4 nanostructures at temperatures of 200 K and 300 K, and a superparamagnetic behavior at 350 K. The dielectric spectroscopy studies revealed a dielectric constant (ε') and loss tangent (tanδ) decrease with the increase in the frequency, as well as demonstrating a normal dispersion behavior, which is due to the Maxwell-Wagner type of interfacial polarization. The values of ε' and tanδ were observed to increase with the increase in the temperature.

Anomalous Phase Transition, Polarization Switching, and Relaxation in a Novel Composite Consisting of Dimethylammonium Aluminum Sulfate Hexahydrate and Oxidized Multiwalled Carbon Nanotubes

A novel ferroelectric composite consisting of dimethylammonium aluminum sulfate hexahydrate (CH3)2NH2Al(SO4)2·6H2O and oxidized multiwalled carbon nanotubes was developed to investigate its dielectric relaxation, phase transition, and ferroelectric switching behaviors. Experimental methods combined with theoretical analyses were employed. The results showed that the filler of oxidized multiwalled carbon nanotubes caused the freezing of domain-wall motion in (CH3)2NH2Al(SO4)2·6H2O at 98.2 K, leading to a decrease in dielectric constant, dielectric loss, and the polarization. In addition, an increase in dielectric permittivity and dielectric loss was found at higher temperatures. The role of hydroxyl groups incorporated in the carbon nanotubes after its oxidation was responsible for the obtained anomalies.

Comparing the Dielectric Properties of Papaya Oil with Mineral Insulating Liquid under Temperature Variation

Abstract: The world’s energy requisite has been controlled by petroleum oil for a long time in transportation, household and power sectors. Mineral Transformation Oil (MTO), being an essential insulating material in transformers, has been used for over fifteen decades. MTO application in the power sector could be hazardous to the environment, especially during a transformer explosion which may cause a spill of oil to the soil or water stream. Owing to the threat of MTO to environment aspects, alternative insulating oil with biodegradable characteristics has attracted a lot of devotions in recent studies. To validate the aptness of using Purified Papaya Seed Oil (PPSO) as an insulating fluid in an electric transformer, it is vital to compare dielectric properties of PPSO with that of MTO insulating liquid. This study presents a comparison of temperature effect on dielectric properties of PPSO with the MTO insulating liquid. Breakdown voltage, dissipation factor (tan δ) and dielectric constant were measured by existing established testing standards. The breakdown voltage was determined by IEC 156 standard test method, whereas the dissipation factor and dielectric constant were determined based on IEC 60247 standard test method. The results revealed that the variation of dielectric properties of PPSO due to temperature change was similar to that of MTO. However, the dissipation factors and breakdown voltages of dielectric properties of PPSO were better when compared with those of MTO at higher temperatures, but with a slight decrease in dielectric constants with the increase in temperature. Keywords: Papaya seed oil, Dissipation factor, Dielectric constant, Breakdown voltage, Temperature, Transformer. PACS: 77.84. Nh, 88.05. Lg.

Evolution and mechanism for the terahertz dielectric spectrum of coal during oxidation

In this paper, the dielectric spectrums of lignite during oxidation and its corresponding dielectric response mechanisms were investigated by means of THz-TDS and synchronous thermal analyzer, combined with the Clausius-Mossotti equation and chemical reaction pathway. Results indicate that dipole polarization is the dominant polarization mechanism during coal oxidation in the THz field. There are four dielectric response mechanisms, which gradually participate in the competition of polarity changes with the increase of oxidation temperature. The dielectric response of lignite shows significant temperature dependence. The dielectric constant first decreases until 150 °C due to the dewatering. From 150 °C to 275 °C, the dielectric constant tends to increase. Before 225 °C, the increase is due to the formation of more oxygen-containing bonds. Beyond 225 °C, the coupling effect of the formation of oxygen-containing bonds and the twisting deformation of the molecular chain skeleton become the main reason. Then, due to the fracture of polar bonds, the dielectric constant drops significantly until 400 °C. Beyond 400 °C, the dielectric constant increases, possibly due to enhanced electron migration. The outcomings of the current study help to identify the oxidation stage of coal and enrich the application basis of THz technology in the fields of coal fire identification and mineral processing.

Influence of La3+ substitutions on structural, dielectric and electrical properties of spinel cobalt ferrite

La3+ doped cobalt ferrites with composition CoLaxFe2−xO4 (0.00 ≤ x ≤ 0.20) were synthesized by a co-precipitation method. X-ray diffraction (XRD) analysis confirm the formation of single-phased spinel structure for all synthesized samples. The result of La3+ doping on dielectric and electrical properties of cobalt ferrites was investigated. Dielectric constant and dielectric loss decrease with increasing frequency whereas alternating current (AC) electrical conductivity increases with increasing frequency. The AC electrical conductivities were effectively modeled by employing the Jonscher’s power law. Role of grain and grain boundary on impedance has been explored from nyquist plots and equivalent electrical circuits were proposed to clarify the impedance spectroscopy results. The Direct Current (DC) electrical resistivities were estimated by two probe method within the temperature range of 303K–700K. DC electrical resistivity decreases with increasing temperature and explained by hopping mechanism. DC electrical resistivity and drift mobility decreases with La3+ doping. Activation energies were calculated by employing the Arrhenius plot. Activation energy found to increases with La3+ substitutions. Maximum value of DC electrical resistivity achieved was 9.26 x 10+8 (Ω-cm) with crystallite size 17 nm. Current-Voltage (I–V) measurements were carried out within 0→6V→0V→ –6V→0V voltage range. It is worth mentioning that all doped sample exhibited remarkable and improved nonlinear hysteresis loop-type behavior than pour sample. Variation in resistance, in current-voltage loops, is clarified by considering space charge limited conduction (SCLC) model and oxygen vacancies migration across the metal-semiconductor interface. Out study suggest that La3+ doped cobalt ferrites may be tested as an active material for possible applications in non-volatile memory devices and neuromorphic applications.

Magnetic, Electric and Optical Properties of Ion Doped CuCr2O4 Nanoparticles

The magnetic, electric and optical properties of pure and ion doped CuCr2O4 - bulk and nanoparticles are investigated theoretically. The magnetization Ms and the band gap Eg decrease with increasing particle size. By Co ion doping Ms and the polarization P show a maximum whereas by Pr ion doping they decrease with increasing the doping concentration. The dielectric constant decreases with enhancing Pr dopants. It is shown that the difference between the doping and host ions radii leads to appearing of a compressive or tensile strain and to different exchange interaction constants in the doped state. Eg decreases by Co doping, whereas it increases by Pr doping.

Preparation of PVA/TiO2 Nanocomposite Films with Various TiO2 Phases by Sol–Gel Technique

The titanium oxide (TiO2) nanoparticles were prepared using the sol-gel technique. The calcination temperature (650, 850) has produced the different TiO2 structures (anatase and rutile), and the effect of the calcination temperature of particles was studied. (TiO2) on the structural properties of the prepared nanomaterial. Furthermore, at room-temperature casting process was used to create a PVA/TiO2 nanocomposite with different TiO2 phases. showed the results of X-ray diffraction (XRD) that a qualitative tetragonal crystal structure (antase, rutile) and scanning electron microscopy FE-SEM used to confirm the microstructure of TiO2 nanoparticles and the effect of each of the calcinations (650, 850) and weight percentages (0.2, 0.4, 0.6, 0.8, 1 wt%) from titanium dioxide nanoparticles on electrical properties of the prepared polymeric (PVA) films. The A. C. conductivity, dielectric constant, and the influence of frequency on the value of A. C. conductivity have been investigated. The results of the electrical properties of alternate current have shown that the dielectric constant decreases with increasing the frequency of the applied field and that alternative conductivity and dielectric constantincrease by increasing the concentration of the nanoparticle.

Study of dielectric and electrical properties in Co-(Fe–Ce-Nd) nanosized spinel ferrites

Ce–Nd doped Cobalt ferrite nanoparticles having composition CoFe2-2xCexNdxO4 (where 0.00 ≤x ≤ 0.10) were prepared by co-precipitation method. X-ray diffraction study confirms the formation of single-phase spinel ferrite. Temperature dependent dielectric and electrical properties has been studied with in the frequency range of 20Hz to 3 MHz. Dielectric constant and dielectric loss decrease as frequency increased while ac conductivity exhibit increasing trend with increasing frequency. The alternating current (AC) conductivity data were successfully modeled by using universal Jonscher's power law which implies that hopping of charge carriers is the governing mechanism in the conduction. Impedance study using Nyquist plots shows that grain boundary resistance is higher than the grain interior resistance. Diameter of Nyquist plots decreases with increasing temperature indicating the decrease in impedance and increase in conductivity. DC resistivity show decreasing trend with increasing temperature revealing semiconductor nature of synthesized nanoparticles. Current–Voltage measurements exhibit nonlinear hysteresis loop which authenticate the occurrence of resistance switching effect in synthesized composition.

Substrate Dielectric Constant Effects on the Performances of a Metasurface-Based Circularly Polarized Microstrip Patch Antenna

This paper presents the effects of substrate dielectric constants on the performance characteristics of a circularly polarized (CP) metasurface-based patch antenna. The antenna structure is a modified patch with a step-like truncation sandwiched between a metasurface composed of a 4 × 4 lattices of periodic metallic patches and a ground plane. The effects on the performance variations are evaluated for two principal cases that include a uniform dielectric constant and a nonuniform dielectric constant for the upper and lower substrates of the antenna. Through careful computational analysis, the effects of the substrate dielectric constant on the antenna performance in terms of bandwidth and gain were investigated, and the results demonstrate that the antenna performance improves with a decrease in the substrate dielectric constant. For a uniform substrate material with dielectric constants of εr1 = εr2 = 2.2, the fabricated antenna with an overall size of 54 mm × 54 mm × 3.0 mm (0.76λo × 0.76λo × 0.042λo at 4.24 GHz) demonstrates the following measured performance characteristics: a −10 dB impedance bandwidth of 3.75–5.24 GHz (33.14%), a 3 dB axial ratio (AR) bandwidth of 3.85–4.64 GHz (18.61%), a radiation efficiency >93%, and a peak gain of 8.96 dBic within the AR bandwidth.

Investigation of structural, electrical and magnetic properties of MnAlxFe2-xO4 ferrite nanoparticles processed by solution combustion route

Al doped Mn ferrite, MnAlxFe2-xO4 (x = 0.1, 0.2, & 0.3), nanoparticles were synthsized by facile and simple solution combustion route. Effect of Al3+ ions substitution on the structural, optical, electrical and magnetic properties were explored. X-Ray diffraction (XRD) results confirm the formation of pure cubic phase for all the synthesized nanoparticles having spinel structure. Various structural parameters like crystallite size, lattice parameter, site radii and bond lengths were estimated from XRD data. For the strain analysis and consideration of contribution of every peak in XRD data, W-H and N-R plots were analysed. Scannining electron microscopy (SEM) revealed the compact surface morphology with grain size in nano meter range. FTIR spectra confirmed the presence of metal stretching vibrations at tetrahedral and octahedral sites for all MnAlxFe2-xO4 nanoparticle compositions, which is typical of spinel ferrites with FCC structure. Raman spectroscopy helped in analysing metal stretching vibrations of the synthesized samples and obtained raman modes were found to be as predicted by group theory. Dielectric constant decreases with increase in frequency reflecting the normal behaviour of the ferrites. Dielectric loss also followed the same trend. Both the behaviours have been explained in view of Koop׳s theory and Maxwell–Wagner polarization-model. The synthesized ferrite samples exhibited the soft magnetic nature as confirmed by vibrating sample magnetometer. The room temperature hysteresis curves indicate the decrease in saturation magnetization as well as retentivity with the increase in Al3+ ions doping. The decrease in magnetic moment values have been explained on the basis of cation preference for the sites and also on weakening of exchange interaction upon aluminium doping.

Analysis of the influence of trivalent Cr3+ doping on the structural and electromagnetic properties of Cu0.5Mg0.5CrxFe2−xO4 nanoferrites

In this inspection, the structural, microstructural, electrical, and magnetic properties of Cr-doped Cu0.5Mg0.5CrxFe2−xO4 (x = 0.0, 0.04, 0.08, 0.12, and 0.16) composites were examined, which were prepared using the sol–gel technique. The x-ray diffraction patterns of the samples sintered at 700 °C for 5 h demonstrate the production of single-phase spinel ferrite. FESEM images indicate a nearly homogeneous surface morphology with non-spherical particles. The average grain size was found to decrease with the Cr concentration. The EDS spectroscopy study of the parent composition and a representative sample of doping composition (x = 0.08) revealed the existence of doped Cr, as well as Fe, Mg, Cu, and O, in the sample. The fluctuation of Cr doping has a significant impact on the magnetic characteristics. The saturation magnetization (Ms) declines as the Cr level grows up to x = 0.08 and then again increases with the increasing Cr content, which may be due to antiferromagnetic Cr not remaining at B sites. Permeability measurements show a similar trend as well. This is expected since μ′ is proportional to Ms squared and grain size. The imaginary part of the permeability decreases with increasing frequency and remains almost constant in the high frequency region. The dielectric constant decreases with frequency increment and remains almost persistent in a higher frequency range. The dielectric permittivity increases with the increasing Cr content up to x = 0.08 but then decreases for greater Cr concentrations. Lower hopping probabilities across grain boundaries may explain the decreasing tendency of the dielectric measurement and rising resistivity with Cr doping after the x = 0.08 concentration. These samples are well-suited for use in high-frequency systems due to their low dielectric loss.

High heat‐resistant (250°C) epoxy resin composites with excellent dielectric properties

AbstractInsulated gate bipolar transistor (IGBT) is the core of electric energy conversion and circuit control, which is widely used in the field of electric vehicles. Higher service temperature, higher power density, and higher operating voltage are the tendency for IGBT in which packing materials have to possess more stable temperature resistance and better insulating properties. In this work, cyanate ester (CE) and polyhedral oligomeric silsesquioxanes (POSS) are introduced into epoxy with various filling ratio to improve the dielectric and thermal properties. The curing process of every system is determined by non‐isothermal differential scanning calorimetry (DSC). N and Si element distribution mappings indicate that there are good compatibility between POSS, CE, and epoxy. The dielectric test shows that the dielectric constant decreases from 4.34 to 2.84 at 1 MHz and from 4.76 to 2.93 at 1 kHz when the filling ratio is 60 wt%. Meanwhile, the DC breakdown strength increases from 172.7 to 286.4 kV/mm. Furthermore, the glass transition temperature (Tg) increases from 180 to 263°C and the yield of residual carbon increases from 6.2% to 23.7%. A new packing material, which can endure 250°C of operating temperature and has excellent dielectric properties has been synthesized.

DFT modelling studies of spectroscopic properties and Medium Effects on Molecular Reactivity of Secnidazole in different solvents

The spectroscopic and optoelectronic investigations of (hydroxyl-2-propyl)-1-methyl-2-nitro-5-imidazole (secnidazole, C_7 H_11 N_3 O_3) molecule were performed using C13 and H1 NMR chemical shifts, FT-IR spectroscopies. Molecular geometric optimizations, HOMO-LUMO properties and molecular electrostatic potential (MPE) were studied using B3LYP functional in DFT method at the cc-pVDZ basis set. UV-Vis spectra of the titled molecule in several solvents (water, dimethyl sulfoxide (DMSO), nitromethane, acetone, and tetrahydrofuran (THF) were investigated theoretically with the aforementioned model method. The solvents have an effective role in the optoelectronic properties of the secnidazole molecule. From non-polar to polar solvents, the (HOMO and LUMO) bandgap energy of secnidazole was found to be decreased except THF solvent. Furthermore, the research aims at investigating the medium effects on solvation free energy, polarizability, dipole moment, first-order hyper-polarizability as well as several molecular properties such as chemical potential, electronegativity, chemical hardness and softness, electrophilicity index of secnidazole (SNZ). The aforementioned method and basis set was used for all kinds of computations in the gas phase and solution. The Solvation Model on Density (SMD) was applied to the aforementioned solvent systems to calculate the solvent polarity effect on dipole moment, free energy, and molecular properties of the (SNZ) molecule. The free energies have gradually increased with a decrease in the solvent dielectric constant i.e. as solvent polarity decreases, the solvation energy increases. From polar to non-polar solvents, the dipole moment of secnidazole was found to be decreased. In various solvents, the dipole moment of secnidazole was greater than that of the gas phase. With the decrease of the solvent dielectric constant, the first-order hyperpolarizability and polarizability have also been decreased. Besides, electronegativity, the chemical potential, and electrophilicity index were decreased continuously from polar to non-polar solvent, except in THF. Secnidazole’s electronegativity, chemical potential, and electrophilicity index were higher in THF than in acetone. However, with increasing solvent polarity, chemical hardness decreased and the inverse relationship was noticed in the case of chemical softness. The obtaining results in this computational investigation may lead to a better understanding of the stability and reactivity of secnidazole and will be helpful for the use of the title compound as reaction intermediates and pharmaceuticals.

Dielectric property and electrical conductivity of ZnS_PVK nanocomposites

The Zinc Sulphide (ZnS)/poly (N-vinylcarbazole) (PVK) nanocomposites thin films for various ZnS concentrations were synthesized by chemical casting method. The thin films are characterized by X-ray diffraction (XRD), which shows the crystalline structure of ZnS in a polymer matrix. The Atomic Force Microscope (AFM), Scanning Electron microscope (SEM) and XRD patterns show an increase in particle size and decrease in roughness with an increase of the ZnS concentration in PVK. The electrical properties of the nano-composites such as conductivity, dielectric constant, and dielectric loss have been investigated. The dielectric constant decreases whereas dielectric loss and conductivity increase as a function of ZnS.

Magnetic and electric properties of multiferroic CuBr[formula omitted

We propose a microscopic model in order to investigate the multiferroic properties of CuBr2 in dependence on temperature, size, magnetic field and ion doping. Using a Green’s function technique we have calculated the magnetization, the heat capacity, the polarization and the dielectric constant. The specific heat has at the magnetic transition temperature TN a clear peak which disappears by applying an external magnetic field h. The polarization increases whereas the dielectric constant decreases with increasing h due to strong magnetoelectric coupling. In a CuBr2 nanoparticle appears a weak ferromagnetism due to the uncompensated spins on the surface. The magnetization increases with decreasing nanoparticle size. The Neel temperature rises strongly applying by ion doping a compressive strain and decreases by a tensile strain.

Influence of MnO2 Nanoparticles Addition on Structural, Optical and Dielectric Characteristics of PVA/PVP for Pressure Sensors

Films of PVA/PVP/MnO2 nanostructures were fabricated for pressure sensors fields with lightweight, flexible and low cost compare with other sensors. The structure, dielectric and optical characteristics of PVA/PVP/MnO2 nanostructures have been studied. The results showed that the dielectric constant, dielectric loss and A.C electrical conductivity of PVA/PVP blend are enhanced with the increase in MnO2 NPs content. The dielectric constant and dielectric loss decrease while the A.C electrical conductivity increases with the increase in frequency. The optical characteristics of PVA/PVP/MnO2 nanostructures showed that the absorbance was rise with increasing of the MnO2 NPs content. The indirect energy gap of PVA/PVP blend was reduced with increase in MnO2 NPs content. The optical constants of blend are changed with the increase in MnO2 NPs content. The pressure sensor application results of PVA/PVP/MnO2 nanostructures showed that the electrical capacitance (Cp) increases with the rise in applied pressure.

Effects of LiF additive on crystal structures, lattice vibrational characteristics and dielectric properties of CaWO4 microwave dielectric ceramics for LTCC applications

In this paper, CaWO4-x wt.% LiF (x = 0.5–3.0) microwave dielectric ceramics are prepared by conventional solid-state reaction at 850 °C. All the X-ray diffraction peaks are attributed to CaWO4, combined with the results of X-ray photoelectron spectroscopy and scanning electron microscope. They indicate that LiF forms liquid phase at high temperature, exists in amorphous phase, and the CaWO4-x wt.% LiF samples belong to the composite ceramics. With the increase of the LiF content, the liquid phase fills the pores of the ceramics and increases the compactness. Therefore, the quality factor increases from 59,055 GHz (x = 0.5) to 77,855 GHz (x = 3.0), and the dielectric constant decreases from 9.26 (x = 0.5) to 8.41 (x = 3.0). The lattice vibration characteristics of the CaWO4-x wt.% LiF samples are studied by Raman and infrared spectroscopy. The external modes associated with the vibration of the Ca–O bonds have the greatest influence on the dielectric response, as shown by the fitting results based on the four-parameter semi-quantum (FPSQ) model. In addition, the simulated intrinsic properties and measured values are in general agreement. When the x value increases, the dielectric constant decreases with the decrease of the bond length. The quality factor has a negative correlation with the FWHM value of the Bg mode and a positive correlation with the packing fraction. Finally, the CaWO4-3 wt.% LiF sample has good compatibility with the silver powders at 850 °C, and high application value in the LTCC field.

Structural, microstructural, spectral, and dielectric properties of erbium substituted spinel ferrites

The Erbium substituted manganese spinel ferrites were prepared via the microemulsion route. The average crystallite size varies from 10.21 to 17.41 nm, while the lattice constant observes to increase from 8.473 to 8.509 Å. X-ray density increases with the incorporation of Er3+ ions in manganese ferrites. The characteristic bands lie in the range of 410–560 cm−1 which confirms the cubic structure of synthesized ferrites. The band variation is evidence of the successful substituting of Er3+ ions in manganese spinel ferrites lattices. Bond lengths increase with the increase of Er3+ content. The dielectric constant, dielectric loss, and tan loss decrease as frequency and Erbium concentration increase. Scanning electron microscopy (SEM) micrographs reveal the decrease in grain size with Er3+ in manganese ferrites. The obtained results suggested that synthesized ferries can be potential candidates for high-frequency applications.

Dielectric constant of aqueous solutions of proteins and organic polymers from molecular dynamics simulations.

The dielectric constant of water/oligomer mixtures, spanning the range from pure water to pure oligomeric melts, is investigated using molecular dynamics (MD) simulations. As prototypical water-soluble organic substances, we consider neutral poly-glycine, poly-ethylene glycol, and charged monomeric propionic acid. As the water content is reduced, the dielectric constant decreases but does not follow an ideal mixing behavior. The deviations from ideal mixing originate primarily in the non-linear relation between the oligomer mass fraction and collective polarization effects. We find that the dielectric constant is dominated by water polarization, even if the oligomer mass fraction exceeds 50%. By a double extrapolation of the MD simulation results to the limit of vanishing water fraction and to the limit of infinite oligomeric chain length, we estimate the orientational contribution to the dielectric constant of the pure polymeric melts. By this procedure, we obtain ɛ = 17 ± 2 for polyglycine and ɛ = 1 ± 0.3 for polyethylene glycol. The large difference is rationalized by polarization correlations of glycine units. Interestingly, we find constant temperature simulations to outperform replica exchange simulations in terms of equilibration speed.

Influence of Zn+2 Doping on Dielectric Properties of Ba-Based Nanoferrites

The effect of frequency, temperature, and composition on the dielectric behavior for the composition of BaNi2-xZnxFe16 O27 ferrite samples were studied (with x = 0, 0.4, and 1.6) prepared using the usual ceramic method. The experimental results indicated that the dielectric constant  and dielectric loss “decrease as the frequency increases, and increases with increasing temperature. The experimental results indicated that the dielectric constant and dielectric loss  decreases. The dielectric constant has high values and shows relaxation processes at relatively higher temperatures. The dielectric abnormal behavior of the dielectric constant was observed to shift to lower values as the temperature increases. The dielectric loss tangent initially decreases rapidly with increasing frequency, and increasing tan δ with increasing temperature is attributed to thermal activation of electron transport, responsible for dielectric behavior. The , and tanσ were composition-dependent, both decreasing as Zn ion substitution increases.