Showing papers on "Relative permittivity published in 2010"

Microwave Dielectric Ceramics in Li2O–Bi2O3–MoO3 System with Ultra-Low Sintering Temperatures

Abstract: A series of compounds in the Li2O–Bi2O3–MoO3 ternary system were investigated with regard to the preparation, phase composition, microwave dielectric properties, and chemical compatibility with silver (Ag) and aluminum (Al) electrodes. All the ceramics in this work have sintering temperatures lower than 750°C. The sintering behaviors and microwave dielectric properties of three single phases Li2MoO4, (Li0.5Bi0.5)MoO4, and Li8Bi2Mo7O28 bulk ceramics, were of particular focus in this investigation. The Li2MoO4 ceramic can be sintered to a high density at 540°C/2 h with a relative permittivity ∼5.5, a Q×f value of 46 000 GHz, and a temperature coefficient of resonant frequency (TCF) of ∼−160 ppm/°C. The (Li0.5Bi0.5)MoO4 ceramic has a scheelite structure and the largest relative permittivity of 44.4 among the ceramics studied in this work with a sintering temperature around 560°C, a Q×f value of 3200 GHz, and a large positive TCF of ∼+245 ppm/°C. The Li8Bi2Mo7O28 ceramic could be sintered at 540°C and has a relative permittivity of 13.6, a Q×f value of 8000 GHz, and a small negative TCF value of ∼−59 ppm/°C. From the X-ray diffraction analysis of cofired ceramics, the Li2MoO4 ceramic does not react with either Ag or Al powders. The Li8Bi2Mo7O28 ceramic reacts with Ag but not with Al at its densification temperature. The (Li0.5Bi0.5)MoO4 ceramic was found to strongly react with Ag powder and to a limited extent with Al powders. From this study, the Li2O–Bi2O3–MoO3 ternary system has a number of attractive new materials with low sintering temperatures, high-performing microwave dielectric properties, chemical compatibility with both Ag and Al metal electrodes, nontoxicity, and low-cost constituents. All these materials can be included in the new field of ultra-low-temperature cofiring dielectrics for multilayer applications.

Dielectric properties of Poly(vinylidene fluoride)/ CaCu3Ti4O12 nanocrystal composite thick films

Abstract: The poly(vinylidene fluoride)/CaCu3Ti4O12 (CCTO) nanocrystal composite films (thickness approximate to 85 mu m) with relatively high dielectric permittivity (90 at 100 Hz) were prepared by the solution casting followed by spin coating technique. The structural, the microstructural and the dielectric properties of the composites were studied using X-ray diffraction, Scanning Electron Microscope, and Impedance analyzer respectively. The effective dielectric permittivity (e(eff)) of the composite increased with increase in the volume fraction of CCTO at all the frequencies (100 Hz to 1 MHz) under investigation. The room temperature dielectric permittivity which is around 90 at 100 Hz, has increased to about 290 at 125 degrees C (100 Hz). These results may be exploited in the development of high energy density capacitors.

Microwave Penetration Depth in Materials with Non-zero Magnetic Susceptibility

Abstract: A simplified equation for determining the transverse electromagnetic mode (TEM) power penetration depth of microwaves in materials having both magnetic and dielectric response was derived. The penetration depths for a magnetite concentrate were calculated using this “full-response” equation, and a significant difference is shown compared with the penetration depth obtained using only the dielectric response (i.e., assuming no imaginary part of complex relative permeability). The temperature dependence of the power penetration depth, up to 1000°C, was determined using measured values of the real and imaginary parts of complex relative permittivity, er′, er″ and permeability, μr′, μr″. The accurate determination of penetration depths can help in optimizing the dimensions of a load in a microwave furnace, producing more uniform heating under microwave irradiation and avoiding thermal runaway.

Simulating polarizable molecular ionic liquids with Drude oscillators.

Abstract: The Drude oscillator model is applied to the molecular ionic liquid 1-ethyl-3-methyl-imidazolium triflate. The range of manageable Drude charges is tested. The strength of the polarizability is systematically varied from 0% to 100%. The influence on the structure, single particle dynamics, and collective dielectric properties is investigated. The generalized dielectric constant can be decomposed into a dielectric permittivity, a dielectric conductivity, and an optical dielectric constant ɛ(∞). The major part of the static generalized dielectric constant comes from the collective rotation of the ions, i.e., the dielectric permittivity. The translational contribution from the dielectric conductivity is about 58% of the dielectric permittivity. For the evaluation of the optical dielectric contribution, the computational dielectric theory was adapted to the case of heterogeneous polarizabilities. In case of 100% polarizability, it reaches a value of approximately 2.

A FDR Sensor for Measuring Complex Soil Dielectric Permittivity in the 10–500 MHz Frequency Range

Abstract: Mechanical details as well as electrical models of FDR (frequency domain reflectometry) sensors for the measurement of the complex dielectric permittivity of porous materials are presented. The sensors are formed from two stainless steel parallel waveguides of various lengths. Using the data from VNA (vector network analyzer) with the connected FDR sensor and selected models of the applied sensor it was possible obtain the frequency spectrum of dielectric permittivity from 10 to 500 MHz of reference liquids and soil samples of various moisture and salinity. The performance of the analyzed sensors were compared with TDR (time domain reflectometry) ones of similar mechanical construction.

Partial discharge control in a power electronic module using high permittivity non-linear dielectrics

Abstract: High electric fields at the edge of the substrate metallization can give rise to partial discharge within power electronic modules and can lead to eventual failure. This paper examines the use of silicone gels filled with barium titanate to reduce the electric field enhancement at the edge of substrate metallization and therefore increase partial discharge inception voltages. The barium titanate filled gel produces a dielectric in which the relative permittivity is increased over a plain gel and that also exhibits a dependence on electric field. The theoretical electric field reduction that can be achieved in a power electronic module through the use of filled gels is demonstrated and compared against experimental measurements including the trial of the technique in some commercial modules. As promising results are achieved, consideration is also given to the effect of the barium titanate filler on the viscosity of the gel and the thermal conductivity, two key manufacturing issues.

Domain wall contributions in Pb"Zr,Ti…O3 ceramics at morphotropic phase boundary: A study of dielectric dispersion

Abstract: The dielectric properties of undoped, Nb-, and Fe-doped Pb(Zr,Ti)O3 ceramics with composition near morphotropic phase boundary were investigated in the frequency range from 1 MHz to 20.2 GHz at room temperature. Temperature dependences of dielectric permittivity e′ and loss e″ are measured at 100 kHz from 50 to 300 K and around 13.4 GHz from 100 to 300 K. These measurements permit estimation of the upper limit of the intrinsic permittivity and lower limit of the extrinsic contributions to the permittivity as a function of temperature. The extrinsic contributions account for more than 50% of the quasistatic dielectric permittivity in studied samples.

Epoxy Based Nanodielectrics for High Voltage DC Applications: Synthesis, Dielectric Properties and Space Charge Dynamics

Abstract: Main goal of the research described in this PhD thesis was to determine the influences of filler size, material and distribution on the DC breakdown strength, permittivity and space charge behaviour of nanocomposites. This should lay the groundwork for tailored insulation materials for HVDC applications. Examples for this are medical and industrial X-ray imaging, radar and cable terminations. In the course of this project a manufacturing process was devised, which enabled the fabrication of epoxy based nanocomposites with a good dispersion of different types of nanoparticles. Models from literature, which explain the behaviour nanodielectrics exhibit, are discussed: electric double-layer model, intensity model, multi-core model and the interphase volume model. Based on these theories, a new model was devised for explaining the behaviour of epoxy based nanocomposites: the polymer chain alignment model. The underlying idea of this model is that the restructuring of the base polymer on the molecular scale, due to the presence of surface modified nanoparticles, plays a fundamental part in the properties of the bulk material. Each modified particle will act as centre for crosslinking of the polymer, leading to a rigid layer of polymer chains around each particle. These rigid layers have a much lower permittivity than both host and filler material, thus their presence can easily be identified by dielectric spectroscopy, since the relative permittivity of the bulk material decreases. In literature it is shown, that the strong bonding of particles and host material due to the surface modification gives rise to improved resistance to partial discharges and electrical treeing. More energy is needed to break these bonds than it would be the case in unmodified polymers. The particles themselves can also act as recombination centres for electrons and holes, which travel between or along polymer chains. This has an effect on the space charge dynamics. Agglomerations of nanoparticles can nullify these effects however: it is explained how agglomerations can act as charge traps, lead to field enhancements and cause interfacial polarization. Claims from theory are tested with three measurement methods: short term DC breakdown tests, dielectric spectroscopy and space charge measurement. It is shown that nanocomposites exhibit improved DC breakdown strength for very low fillgrades of 0.5 to 2 % by weight. Compared to the unmodified base material improvements of up to 80 % could be measured. Dielectric spectroscopy reveals that the relative permittivity in nanocomposites is lower than of the host and filler materials, with a minimum at a fillgrade of approximately 2 % by weight. For higher fillgrades the permittivity of the composite increases depending on the ratio between the permittivity values of filler and host material. Above 2 wt.% the permittivity of the filler material starts to overshadow the low permittivity of the rigid layers around the particles. Results from space charge measurement with the pulsed electro-acoustic method show that the quality of particle dispersion has an impact on the charge intake. Based on these measurements it is concluded that particle agglomerations act as charge traps, while the amount of charges in nanocomposites with good particle dispersion is lower than in the unmodified epoxy. This confirms that the particles indeed act as recombination centres, actively mitigating charge buildup inside the material. These results show why nanocomposites are very interesting for HVDC equipment. Space charges are a limiting factor for DC applications. Their reduction improves the reliability of the insulation system. The increased DC breakdown strength enables more compact high voltage equipment, respectively the utilization at higher field strengths. The work presented here is a stepping stone on the way to industrial applications of nanostructured insulation material and fundament for further investigations on topics like nanofluids.

Prediction of Banana Quality during Ripening Stage Using Capacitance Sensing System

Abstract: Capacitive property of banana fruit was studied in order to develop a rapid and non-invasive ripening assessment method to control their ripening treatment. A sine wave frequency generator with parallel plates capacitor sample was used to span the difference in capacitance, caused by the introduction of a banana fruit into the sensor. Banana fruits were submitted to measurement before ethylene treatment on first day and after treatment for five days. Relative permittivity was correlated with quality parameters of banana fruit. Green-ripe banana fruits have larger permittivity than the full-ripe ones, the permittivity of which was decreased as a result of the ripening stage. Quadratic regression had higher prediction power of the equations than linear regression. Experiments indicated that the best frequency of sine wave was1 MHz. Permittivity at this frequency changed from 1.7433 for green-ripe banana fruits to 1.6431 for full ripe ones after a five-day period.

Low-loss spinel nanoferrite with matching permeability and permittivity in the ultrahigh frequency range

Abstract: Ferrite nanoparticles with a composition of Ni0.5Zn0.3Co0.2Fe2O4 were prepared by a coprecipitation method. The sample obtained after treating at appropriating conditions had almost equal real permeability and permittivity, of 4.8+j0.15 (loss tangent∼0.04) and 4.9+j0.10 (loss tangent∼0.018), respectively, over 100 to 500 MHz. This material had a refractive index n of close to 5 and a reduced impedance Z/Z0 of close to 1. These properties make the material useful to the design of miniaturized antennas at very high frequency-ultra high frequency (VHF-UHF) (100–500 MHz) bands.

Complex permittivity measurements using cavity perturbation technique with substrate integrated waveguide cavities

Abstract: Cavity perturbation technique is widely used in the measurements of complex dielectric permittivity of materials due to its accuracy and ease of configuration. This paper presents the theoretical formulas for the evaluation of complex permittivity of materials using cavity perturbation technique with substrate integrated cavity resonators. With the proposed formulas, the use of various planar cavities is possible by taking into account the dielectric characteristics of the substrate in which the cavity is implemented. Simulations and measurements are performed on various dielectric samples to validate the proposed theory. The maximum deviation in the measured dielectric permittivity values is below 6% compared to the literature values. The implemented substrate integrated cavity is then analyzed in terms of sensitivity, showing a good performance.

Anomalous Increase of Dielectric Permittivity in Sr-Doped CCTO Ceramics Ca1―xSrxCu3Ti4O12 (0≤x≤0.2)

Abstract: Partial substitution of Ca with Sr in high permittivity Ca1−xSrxCu3Ti4O12 ceramics can lead to an anomalous increase in intrinsic bulk dielectric permittivity. The similar electron configuration of Ca and Sr excludes electronic structure variations as a source of this permittivity increase, and thus an alternative mechanism must exist.

Ultra‐Low Firing High‐k Scheelite Structures Based on [(Li0.5Bi0.5)xBi1−x][MoxV1−x]O4 Microwave Dielectric Ceramics

Abstract: In this work, dense ceramic samples across the solid solution of the [(Li0.5Bi0.5)xBi1−x][MoxV1−x]O4 system are prepared using the solid-state reaction process. The monoclinic phase region could be obtained for 0≤x<0.098 and the scheelite tetragonal solid solution region could be obtained for 0.098

Retrieval of Permittivity and Permeability of Homogeneous Materials from Scattering Parameters

Abstract: On the basis of measured scattering parameters, we present a general assessment of the main problems with the Nicholson-Ross-Weir retrieval procedure: First, the inherent instability of the method for low-loss materials at frequencies corresponding to integer multiples of the transmitted wavelength in the sample; second, the multivalued solutions for the complex wavenumber when the electrical length of the sample exceeds a wavelenghth. It is shown that the presence of small perturbation or noise on the transmission coefficient T at around |T| ≈ 1 suffices to trigger the instability when retrieving the impedance of the sample. Unlike the ill-conditioned expression of the impedance, the product μe (refractive index squared) is stable to perturbation in T. For nonmagnetic materials (relative permeability μr = 1), therefore, the product μe reduces to the complex permittivity, which is then correctly retrieved without divergent ripples as shown by the extracted permittivity spectra in the X-band (8.2–12.4 GHz)...

Multi-walled carbon nanotube-based RF antennas

Abstract: A novel application that utilizes conductive patches composed of purified multi-walled carbon nanotubes (MWCNTs) embedded in a sodium cholate composite thin film to create microstrip antennas operating in the microwave frequency regime is proposed. The MWCNTs are suspended in an adhesive solvent to form a conductive ink that is printed on flexible polymer substrates. The DC conductivity of the printed patches was measured by the four probe technique and the complex relative permittivity was measured by an Agilent E5071B probe. The commercial software package, CST Microwave Studio (MWS), was used to simulate the proposed antennas based on the measured constitutive parameters. An excellent agreement of less than 0.2% difference in resonant frequency is shown. Simulated and measured results were also compared against identical microstrip antennas that utilize copper conducting patches. The proposed MWCNT-based antennas demonstrate a 5.6% to 2.2% increase in bandwidth, with respect to their corresponding copper-based prototypes, without significant degradation in gain and/or far-field radiation patterns.

Kramers-Kronig relations for the dielectric function and the static conductivity of Coulomb systems

Abstract: The mutual influence of singularities of the dielectric permittivity e(q, ω) in a Coulomb system in two limiting cases ω→0, q→0 and q→0, ω→0 is established. It is shown that the dielectric permittivity e(q→0, ω) satisfies the Kramers-Kronig relations, which possesses the singularity due to a finite value of the static conductivity. This singularity is associated with the "long tails" of the time correlation functions.

Structural, optical and dielectric behavior of PVDF films filled with different concentrations of iodine

Abstract: Complex formation between polyvinyldene fluoride (PVDF) and different concentrations (≤10 wt%) of iodine were prepared by casting method using dimethyl sulfoxide (DMSO) as a common solvent. Their crystalline structure, optical and dielectric properties were examined. X-ray spectroscopy was adopted for analytical characterization of the films developed for applications. UV–VIS analysis suggests that the addition of iodine leads to formation of charge transfer complex with two different modes. The conductivity and dielectric measurements were carried out on these films as a function of frequency at various temperatures. The addition of iodine significantly improved the ionic conductivity. The conductivity–temperature plots were found to follow an Arrhenius nature. The dielectric behavior was analyzed using dielectric permittivity (e′), dissipation factor (tan δ) and electric modulus (M′ and M″) of the samples. The decrease in dielectric permittivity was observed with increasing frequency and temperature.

Preparation and evaluation of epoxy composite insulating materials toward high thermal conductivity

Abstract: The aim of this study is to improve both thermal and electrical insulation properties of epoxy based composites using nanocomposite techniques. This paper deals with preparation of epoxy composites with high content of micro-filler and those several material characterizations. Types of filler and solvent, methods of mixing and casting were examined to achieve high filler content of more than 80 vol % in a commercial epoxy resin. Thermal conductivity, relative permittivity and dielectric strength were evaluated in each specimen. This study was mainly focused on alumina particles of spherical shape as primary micro-filler. In addition, effects of blending a different alumina, boron nitride, and silicon carbide particles into the alumina filler as secondary micro-filler were investigated on those several properties. As a result, micro-alumina 60 vol% filled epoxy composites of 0.2 mm thick was obtainable, and it was elucidated that its thermal conductivity is 4.3 W/m/K, its relative permittivity is 6.0, and its dielectric strength is 16 kV/mm. It is conclude that epoxy with hybrid fillers is useful for high thermal conductive composite materials for thin electrical insulating substrates.

Electrically Small Magnetic Dipole Antennas With Quality Factors Approaching the Chu Lower Bound

Abstract: We investigate the quality factor Q for electrically small current distributions and practical antenna designs radiating the TE10 magnetic dipole field. The current distributions and the antenna designs employ electric currents on a spherical surface enclosing a magneto-dielectric material that serves to reduce the internal stored energy. Closed-form expressions for the internal and external stored energies as well as for the quality factor Q are derived. The influence of the sphere radius and the material permeability and permittivity on the quality factor Q is determined and verified numerically. It is found that for a given antenna size and permittivity there is an optimum permeability that ensures the lowest possible Q, and this optimum permeability is inversely proportional to the square of the antenna electrical radius. When the relative permittivity is equal to 1, the optimum permeability yields the quality factor Q that constitutes the lower bound for a magnetic dipole antenna with a magneto-dielectric core. Furthermore, the smaller the antenna the closer its quality factor Q can approach the Chu lower bound. Simulated results for the TE10-mode multiarm spherical helix antenna with a magnetic core reach a Q that is 1.24 times the Chu lower bound for an electrical radius of 0.192.

Effect of Dispersive Conductivity and Permittivity in Volume Conductor Models of Deep Brain Stimulation

Abstract: The aim of this study was to examine the effect of dispersive tissue properties on the volume-conducted voltage waveforms and volume of tissue activated during deep brain stimulation. Inhomogeneous finite-element models were developed, incorporating a distributed dispersive electrode-tissue interface and encapsulation tissue of high and low conductivity, under both current-controlled and voltage-controlled stimulation. The models were used to assess the accuracy of capacitive models, where material properties were estimated at a single frequency, with respect to the full dispersive models. The effect of incorporating dispersion in the electrical conductivity and relative permittivity was found to depend on both the applied stimulus and the encapsulation tissue surrounding the electrode. Under current-controlled stimulation, and during voltage-controlled stimulation when the electrode was surrounded by high-resistivity encapsulation tissue, the dispersive material properties of the tissue were found to influence the voltage waveform in the tissue, indicated by RMS errors between the capacitive and dispersive models of 20%-38% at short pulse durations. When the dispersive model was approximated by a capacitive model, the accuracy of estimates of the volume of tissue activated was very sensitive to the frequency at which material properties were estimated. When material properties at 1 kHz were used, the error in the volume of tissue activated by capacitive approximations was reduced to -4.33% and 11.10%, respectively, for current-controlled and voltage-controlled stimulations, with higher errors observed when higher or lower frequencies were used.

Single-colloidal particle impedance spectroscopy: complete equivalent circuit analysis of polyelectrolyte microcapsules.

Abstract: We present a high-speed microfluidic technique for characterizing the dielectric properties of individual polyelectrolyte microcapsules with different shell thicknesses using single-particle electrical impedance spectroscopy. Complete equivalent circuit analysis is developed to describe the electrical behavior of solid homogeneous microparticles and shelled microcapsules in suspension. The complete circuit model, which includes the resistance of the shell layer and the capacitance of the inner core, has been used to determine the permittivity and conductivity in the shell of single capsules. The PSpice circuit simulations, based on the developed complete circuit models, are used to analyze the experimental data. The relative permittivity of the polyelectrolyte capsule shell is determined to be 50, and the conductivities of the shells of six- and nine-layer microcapsules are estimated to be 28 +/- 6 and 3.3 +/- 1.7 mS m(-1), respectively.

Effect of coupling agent on the thermal and dielectric properties of PTFE/Sm2Si2O7 composites

Abstract: The present study investigates the dielectric and thermal properties of PTFE/Sm2Si2O7 composites. The composites were prepared by powder processing technique followed by hot pressing. The variation of the dielectric properties with filler content (0–0.5 Vf) was studied at 1 MHz and 9 GHz. The filler surface was chemically modified using phenyl trimethoxy silane (PTMS) as a coupling agent. The microstructural study using scanning electron microscopy (SEM) showed that the particles were well dispersed in the matrix when coupled with PTMS. The surface modification led to an improvement in the dielectric properties. The PTFE filled with 0.4 Vf silane treated Sm2Si2O7 composite showed a low dielectric loss of 0.0054 and slightly higher relative permittivity of 3.92 when compared with the untreated composite of the same composition. The experimental values of relative permittivities were compared with the theoretical predictions and the Effective Medium Theory was found to agree well even for higher content of silane treated filler. It was found that the addition of silane coupling agent is very effective in improving the thermal properties of the PTFE/Sm2Si2O7 composites.

Dielectric, thermal, and mechanical properties of CeO2-filled HDPE composites for microwave substrate applications

Abstract: Cerium oxide-filled high density polyethylene (HDPE) composites for microwave substrate applications were prepared by sigma-blend technique. The HDPE was used as the matrix and the dispersion of CeO2 in the composite was varied up to 0.5 by volume fraction, and the dielectric properties were studied at 1 MHz and microwave frequencies. The variations of thermal conductivity (keff), coefficient of thermal expansion (αc) and Vicker's microhardness with the volume fraction of the filler were also measured. The relative permittivity (eeff) and dielectric loss (tan δ) were found to increase with increase in CeO2 content. For 0.4 volume fraction loading of the ceramic, the composite had eeff = 5.7, tan δ = 0.0068 (at 7 GHz), keff = 2.6 W/m °C, αc = 98.5 ppm/°C, Vicker's microhardness of 18 kg/mm2 and tensile strength of 14.6 MPa. Different theoretical approaches have been used to predict the effective permittivity, thermal conductivity, and coefficient of thermal expansion of composite systems and the results were compared with the experimental data. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 998–1008, 2010

Dielectric permittivity of room temperature ionic liquids: a relation to the polar and nonpolar domain structures.

Abstract: We measured microwave transmission and reflection spectra for typical room temperature ionic liquids, [C4min][TFSA], [C4min][PF6], [C6min][PF6], and [C8min][PF6], at frequencies between 40 MHz and 40 GHz in the temperature range up to 100 °C. The transmission spectra were analyzed using complex dielectric functions, and the static permittivity eS was determined as a function of temperature. Applying the effective medium approximation to eS, we have estimated that the static permittivity of the polar domain is around 20, and that of the nonpolar domain around 2.5.

Determination of constitutive and morphological parameters of columnar thin films by inverse homogenization

Abstract: A dielectric columnar thin film (CTF), characterized macroscopically by a relative permittivity dyadic, was investigated theoretically. The CTF was assumed, on the nanoscale, to be an assembly of parallel, identical, elongated ellipsoidal inclusions made of an isotropic dielectric material that has a different refractive index from the bulk material that was evaporated to fabricate the CTF. The inverse Bruggeman homogenization formalism was developed in order to estimate the refractive index of the deposited material, one of the two shape factors of the ellipsoidal inclusions, and the volume fraction occupied by the deposited material, from a knowledge of relative permittivity dyadic of the CTF. A modified Newton-Raphson technique was implemented to solve the inverse Bruggeman equations. Numerical studies revealed how the three nanoscale parameters of CTFs vary as functions of the vapor incidence angle.

Complex permittivity characteristics of epoxy nanocomposites at low frequencies

Abstract: The complex permittivity characteristics of epoxy nanocomposite systems were examined and an attempt has been made to understand the underlying physics governing some of the unique macroscopic dielectric behaviors. The experimental investigations were performed using two different nanocomposite systems with low filler concentrations over the frequency range of 10-2-400 Hz, but for some cases, the data has been reported upto 106 Hz for a better understanding of the behaviors. Results demonstrate that nanocomposites do possess unique permittivity behaviors as compared to those already known for unfilled polymer and microcomposite systems. The nanocomposite real permittivity and tanδ values are found to be lower than that of unfilled epoxy. In addition, results show that interfacial polarization and charge carrier mobilities are suppressed in epoxy nanocomposite systems. The complex permittivity spectra coupled with the ac conductivity characteristics with respect to frequency was found to be sufficient to identify several of the nanocomposite characteristics like the reduction in permittivity values, reduction in the interfacial polarization mechanisms and the electrical conduction behaviors. Analysis of the results are also performed using electric modulus formalisms and it has been seen that the nanocomposite dielectric behaviors at low frequencies can also be explained clearly using this formalism.