Dissipation Factor Tan Research Articles

Facile design of a low-cost laser CUT-OFF filter with PMMA polymer nanocomposite doped with Mg0.5Ni0.5Fe2O4: structural, optical, and dielectric properties

This study employed the sol gel auto-combustion approach to synthesize Mg0.5Ni0.5Fe2O4 spinel ferrite nanoparticles. Additionally, the casting method was used to fabricate Mg0.5Ni0.5Fe2O4/PMMA nanocomposite polymer films. The structural properties were analyzed by the utilization of x-ray diffraction pattern (XRD), high resolution transmission electron microscope (HRTEM), and field emission scanning electron microscope (FESEM). The UV-visible spectrophotometer examination was used to evaluate the optical properties of the produced nanocomposite films, such as absorbance, transmittance, indirect energy band gap, Urbach energy, excitation coefficient, and refractive index. Two indirect optical energy gaps are calculated, whereas they decreased from 4.56 eV to 4.33 eV, and from 4.04 eV to 3.01 eV, while the Urbach energy increased from 0.304 eV to 0.524 eV as the nanofillers increased from 0 to 4 wt%. An investigation was conducted to examine the impact of nanoparticle doping on the dielectric constant, electric modulus, and ac conductivity. The Mg0.5Ni0.5Fe2O4/PMMA nanocomposite films demonstrate higher permittivity and ac conductivity and a lower dissipation factor and electric modulus compared to pure PMMA. The dielectric permittivity (ε′) increased from 2.76 to 3.43 at a constant frequency 100 Hz up to 2 wt.% of Mg0.5Ni0.5Fe2O4 then decreased to 2.41 while the dissipation factor tan(δ) decreased from 0.1 to 0.046 at the same frequency. The nanocomposite films are well-suited for utilization in CUT-OFF selective laser filters, solar cells, energy storage devices, and other applications in related industries.

Physico-chemical properties of transformer mineral oils submitted to moisture and electrical discharges

This work is devoted to an accurate investigation on the variations of the physicochemical properties of three transformer mineral oils of different levels of degradation submitted to moisture and electric discharges. The first one is a non treated new oil while the second is taken from a one year normal operating transformer and the third is extracted from a 15 years old operating transformer. The investigated parameters are breakdown voltage, relative permittivity r , dissipation factor (Tan) and resistivity. Each oil peculiarities are determined through these parameters. Measurements on an on load operating transformer are reported to validate some laboratory obtained results.

Low temperature spark plasma sintering of efficient (K,Na)NbO3 ceramics

This study investigates the sintering optimization and characterization of (K0.5,Na0.5)NbO3 (KNN) ceramics using spark plasma sintering (SPS) at low temperatures. The influence of sintering temperature on crystal structure, microstructure, and dielectric properties is explored. KNN ceramics were sintered as low as 400 °C and exhibit a relative permittivity (εr) of 740 and a low dissipation factor (tan(δ)) of 0.02 at room temperature. These findings highlight the potential of SPS-sintered KNN ceramics at low temperatures for applications requiring high permittivity and low dielectric losses.

Novel cobalt lead ferrite (CPFO)/Ps nanocomposites with enhanced structure, optical and dielectric properties

Hexa-spinel ferrite nanoparticles of Cobalt Lead Ferrite (CPFO) were prepared by a flash auto combustion method, while xCPFO/PS (x = 0, 2.5, 5, and 7.5 wt%) nanocomposite films were synthesized by casting method. The diffraction pattern and Rietveld refinement of CPFO nanoparticles proved that they have a face-centred cubic spinel and a hexagonal structure. HRTEM micrographs of cobalt lead ferrite (CPFO) nanoparticles show an average particle size of around 30 nm. FESEM cross-section images of CPFO/PS nanocomposite films showed CPFO nanoparticles dispersed in the PS matrix. All optical characteristics of the synthesized nanocomposite films, including absorbance, transmittance, direct and indirect energy band gap, Urbach energy, excitation coefficient, and refractive index, were investigated using a UV-visible spectrophotometer examination. The direct optical energy band gap lowered from 4.533 eV to 4.368 eV, and the indirect energy optical bandgap lowered from 4.337 eV to 4.146 eV, while the Urbach energy increased from 0.103 eV to 0.209 eV with increasing the nanofillers from 0 to 7.5 wt%. Broadband dielectric spectroscopy was used over a wide frequency range (0.1 Hz–1 MHz). The dielectric real permittivity (ε′), the dissipation factor tan (δ) and the electric modulus (M′&M′′) measurements were studied. CPFO nanoparticles’ addition significantly enhanced the dielectric real permittivity (ε′), the dissipation factor tan (δ), and the ac conductivity of all nanocomposites.

Study on the addition of SiO2 nanowires to BaTiO3: Structure, morphology, electrical and dielectric properties

The effects of adding silicon dioxide (SiO2) nanowires on the properties of barium titanate (BaTiO3) were investigated. The structure, morphology and optical properties were examined using X-ray powder diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and ultraviolet–visible diffuse reflectance spectrophotometry (DR). All of the prepared samples crystallized with a cubic BaTiO3 structure. When the SiO2 content was <2.0 wt%, no secondary phase was observed and the (BaTiO3)1–x/(SiO2)x samples exhibited a microstructure with small grains. However, Ba2TiSi2O8 was detected upon further increasing the SiO2 content. When compared to the pure BaTiO3 sample, a slight increase in the Eg value was observed for the (BaTiO3)1–x/(SiO2)x composites. The dielectric and electrical measurements were used to analyze the dielectric constant (ε′), dissipation factor (tan(δ)), conductivity (σac) and impedance (Z). The results demonstrate that the addition of SiO2 nanowires affects the properties of BaTiO3. The study highlights the importance of SiO2 nanowires in BaTiO3 for use in microwave device applications.

Processing, thermal and dielectric investigations of polyester nanocomposites based on nano-CoFe2O4

The present study aims at developing polyester/CoFe2O4 polymer nanocomposites, with enhanced thermal and electrical properties. The X-ray diffraction data of the samples revealed the semi-crystalline polyester nature and spinel crystal structure of CoFe2O4 nanoparticles. The average crystal size obtained from Scherer equation is 44 nm, which is smaller than that estimated from W–H method (59 nm). FTIR spectroscopy proved the complexation and interaction between polyester segments (–COOH and –OH) and CoFe2O4 nanoparticles via hydrogen ponding. DSC analysis showed changes in Tg values up to 116 °C and polyester/CoFe2O4 have revealed more thermal stability at temperatures Tonset, Tmax and T50 as seen from the TGA-DTG investigations. Dielectric real permittivity (ε′) expressively increased by adding the CoFe2O4 nanoparticles, that is related to Maxwell-Wagner-Sillars (MWS) effect in hetero-phase composites. It has been found that CoFe2O4 nanoparticles enhanced the dissipation factor (tan(δ)) for all nanocomposites. The relative energy density (URelative) values are 4.39, 8.02, 10.7 and 11.3 for the polymer nanocomposites doped with 5.0, 10.0, 15.0 and 20.0 wt% of CoFe2O4 nanoparticles. Finally, the DC conductivity of nanocomposites increased with increasing the CoFe2O4 concentration.

A micromechanical model to predict the viscoelastic response of syntactic foams

Syntactic foams are light-weight novel composites that have gained importance over conventional materials due to their low weight and high specific mechanical properties. They are two- phase composites consisting of a matrix embedded with hollow glass microspheres. Various micromechanics-based approaches exist to evaluate the bulk properties of the composite. In this study, a generalized self- consistent three-phase method is used to determine the bulk properties of the composite (elastic, shear moduli and the Poisson’s ratio) analytically. Parametric studies are carried out to study the effect of microsphere wall thickness and radius on the bulk properties. The inaccurate assumption of a perfectly elastic matrix is replaced by introducing viscoelasticity in the matrix and evaluating the shear response of the resultant composite. The hysteresis response of the composite and the energy dissipation factor tan(δ) are studied at different frequencies and volume fractions.

Surface morphology and electrical transport properties of Aberchrome 670 ( (E-3(admantan-2-ylidene) -4-[1-(2,5-dimethyl-3-furyl) ethyldene] dihydro-2,5-furandione)) nano thickness films

In this paper, surface morphology and electrical properties of Aberchrome 670 , [(E-3(admantan-2-ylidene)-4-[1-(2,5-dimethyl-3-furyl) ethyldene] dihydro -2,5-furandione)], thin films with nano thickness, have been studied, for the first time, to provide one with knowledge concerning microscopic features, for electrical applications of organic photochromic compounds. The atomic force microscope (AFM) has been used to convene a general spectacle about the surface. The cyclic-voltammetric measurement has been inserted to determine the electrochemical gap. The thermal effect on the electrical resistivity, the thermoelectric power and Seebeck coefficient have been measured from 298 to 373 K. The influence of the frequency on some dielectric characteristics; such as the capacitance, the temperature capacitance coefficient (T.C.C), the real part of the complex dielectric permittivity (), the dissipation factor (tan (δ)) has been studied in the frequency zone (50 -5 MHz) and temperature range (∼298–373 K) at different steady temperatures.

Effect of acceptor and donor dopants (Na, Y) on the microstructure and dielectric characteristics of high Curie point PZT-modified ceramics

This study describes the preparation of a solid solution of $${\text{Pb}}^{2 + } [({\text{Zr}}_{0.05}^{4 + } ,{\text{Ti}}_{0.95}^{4 + } )_{0.97} ({\text{Al}}_{1/3}^{3 + } ,{\text{Zn}}_{1/2}^{2 + } ,{\text{W}}_{1/3}^{6 + } )_{0.03} ]{\text{O}}_{3}$$ (PZT) based on the mixed oxide method. A different amount of sodium carbonate and yttrium oxide (0.03 at.%, 0.06 at.%, and 0.1 at.%), where the ratio of Na:Y = 1:1 by mole, was added to PZT to investigate the effect of Na and Y co-doping. The ceramic samples were sintered and then subjected to phase identification, physical properties determination, and dielectric properties measurement. It was assumed that, by integrating into the lattice parameters, there is a substitution preference alternation of Y3+ for host cations in the perovskite lattice, while Na+ replaces the A-position of Pb2+ in the lattice. This resulted in more oxygen vacancy being generated in the lattice. PZT–xNY compositions exhibited an obvious anomaly in the temperature dependence of dielectric loss and dielectric permittivity below the phase transition temperature. In addition, it was found that doping of 0.1 at.% Na and Y resulted in a maximum dielectric constant (ec$$\sim 10,400$$) at Curie temperature (~ 749 K) with dissipation factor tan(δ)$$\sim 2.798$$%. Moreover, the diffusivity estimated using the modified Curie–Weiss law obtained at 1 kHz for all compositions showed that the material exhibits a diffuse-type phase.

Structural, Optical and Frequency Dependent Electrical Behaviour of Aluminum Nitride (ALN) Nanopowder

Aluminum nitride (AlN) is ceramic material. It has very high thermal and low electrical conductivity. The Variation of Various Electrical Parameters viz. Impedance (Z), Admittance (Y), Dielectric Permittivity ('), Relative Loss (''), Electrical Conductivity (), and Loss Tangent (Tan ) with frequency Dependence of Aluminum Nitride (AlN) Nano powder were studied. Scanning electron microscopy (SEM); Raman Spectroscopy; and X-ray diffraction (XRD) were used to analyse the surfaces and structures of aluminum nirtride nanopowder. It has been found that the particle size is of 36.15 nm and the crystallographic structure is amorphous. The surface morphology of the studied compound has been investigated by Scanning Election Microscopy (SEM) indicating the particles are in nanosize and characteristic range of diameters are in nanoscale. The electrical studies of the studied compound have been examined in order to acquire the electrical parameters (mainly dielectric permittivity, loss, conductivity, loss-tangent, impedance, and admittance). Small rise in the conductivity (with frequency dependent) has been observed due to the decrease in the particle size of the material.it is also observed that the relative permittivity ('), relative loss '') and dissipation factor (Tan ) decreases with increase in frequency. The Raman shift variation with the intensity which shows the peaks of the compound are obtained at 506 cm-1, 615 cm-1 656 cm-1, 873 cm-1, 882 cm-1, 949 cm-1, and 974 cm-1using laser at 785 nm.

The Magneto-Dielectric Anisotropy Effect in the Oil-Based Ferrofluid

The dielectric parameters of an oil-based ferrofluid with magnetic nanoparticles were measured in combination with a magnetic and electric field. Three types of measurements were carried out over wide frequency ranges from 10 mHz to 2 MHz, at various temperatures, using a capacitance method. The magneto-dielectric effect of the dissipation factor (tan $$\delta $$ ) was observed for constant magnetic flux density of value 200 mT. In a magnetic field, the interaction between the magnetic field and the magnetic moments of nanoparticles leads to the aggregation of magnetic nanoparticles into various structures. In these structures were rearranged charges around nanoparticles which had an influence on their dielectric parameters. These parameters were also measured over a linear increase and decrease of the magnetic flux density to 200 mT. The dependence of the real part of a complex dielectric constant and tan $$\delta $$ at constant magnetic flux density in dependence on the angle with the electric field (anisotropy) were also measured. These parameters were changed linearly with increasing angle and dependent on the temperature. From the monotonic change of studied parameters with angle resulted that thin chains of nanoparticles were created in the ferrofluid.

Dielectric spectroscopy of Ag-starch nanocomposite films

In the present work Ag-starch nanocomposite films were fabricated via chemical reduction route. The formation of Ag nanoparticles was confirmed using transmission electron microscopy (TEM). Further the effect of varying concentration of Ag nanoparticles on the dielectric properties of starch has been studied. The frequency response of dielectric constant (ε′), dielectric loss (ε″) and dissipation factor tan(δ) has been studied in the frequency range of 100 Hz to 1 MHz. Dielectric data was further analysed using Cole-Cole plots. The dielectric constant of starch was found to be 4.4 which decreased to 2.35 in Ag-starch nanocomposite film containing 0.50 wt% of Ag nanoparticles. Such nanocomposites with low dielectric constant have potential applications in microelectronic technologies.

Effect of Sn substitution for Se on dispersive optical constants of amorphous Se–Te–Sn thin films

ABSTRACTOptical constants of vacuum evaporated thin films in the Se90−xTe10Snx (x = 0, 2.5, 5 and 7.5 at %) system were calculated from reflectance and transmittance data in the wavelength range of 300–2500 nm using Murmann’s equations. The maximum value of refractive index increased and suffered a shift towards the short wavelength as the Sn content increases this behavior can be attributed to increasing the values of cross-linking chains density and decrease tailing. The variations in the real and the imaginary parts of the dielectric constant, the dissipation factor tan(δ), the optical conductivity, the volume, and surface energy loss functions with photon energy have also been reported. The normal dispersion of the refractive index is discussed regarding the single oscillator Wemple-DiDomenico model from which the dispersion parameters were determined. The single oscillator energy, the dispersion energy, the high-frequency dielectric constant, the ratio of free charge carrier concentration to the effective mass, plasma frequency, single oscillator strength and its position are then estimated as a function of alloy composition. It is interesting to note that the increase of Sn content on the parent Se90Te10 is connected to the decreasing covalent nature of the structure. Besides, the presence of such a sharp absorption edge in transmission spectra recommends Se90−xTe10Snx thin films as a good optical filter material.

Understanding the dielectric properties of pressboard material thermally aged in Dibenzyl Disulphide (DBDS) included transformer oil

Surface Discharge Inception Voltage (SDIV) of unaged and copper sulphide diffused Oil Impregnated Pressboard (OIP) material was studied by adopting Ultra High Frequency (UHF) technique. Copper sulphide diffusion into OIP material was carried out by thermal aging of pressboard material in Dibenzyl Disulphide (DBDS) added transformer oil. The SDIV reduces with increase of thermal aging temperature. The current pulse injected in positive and negative half cycle during the surface discharge of the AC shows the rise time of 0.8ns and 1ns respectively. The FFT analysis of UHF signal measured during surface discharge process has shown frequency content in the range 0.7–1.2 GHz with its dominant frequency at 0.9 GHz. The life of the charge presented on the pressboard increases with thermal aged specimen. Energy dispersive spectroscopy (EDS) analysis of OIP material indicates presence of copper and sulphur content. Frequency Domain Dielectric Spectroscopy (FDDS) studies indicate the permittivity(er), dissipation factor (tan(δ)), conductivity (σdc) increases and relaxation time (τ), coefficient (α) decrease with OIP material (in air / Nitrogen) aged at higher temperature in DBDS added transformer oil. Cole-Cole double relaxation model was used to understand the dielectric parameters of copper sulphide diffused OIP material. The DC conductivity of pressboard material aged in DBDS included transformer oil follows Arrhenius law and the activation energy decreases with increase in temperature of thermal aging.

Experimental Study of Adulteration Detection in Fish Oil Using Novel PDMS Cavity Bonded EBG Inspired Patch Sensor

In this paper, a high impedance surface electromagnetic bandgap inspired resonator patch, bonded with a polydimethylsiloxane (PDMS) cavity was implemented as a sensor device for detecting adulteration in a fish oil dietary supplement. The fabricated sensor on a Neltec substrate of relative permittivity ( $\varepsilon _{r}= 3.2$ ) and dissipation factor (tan $\delta = 0.007$ ) has a unique pattern of electromagnetic bandgap unit cells, and offers TM01, TM11, and TM21 transverse magnetic modes for dielectric spectroscopy of the sample. The measured reflection coefficient at 2.592 GHz of the air-filled PDMS cavity bonded to the patch sensor under TM01 mode was used for calibrating the sensor subjected to 10%, 20%, 30%, 40%, and 50% adulteration in the fish oil. With olive oil as an adulteration ingredient inside fish oil, a maximum shift of 70 MHz was observed in the sensor frequency response for 50% adulteration level. A linearity of more than 91% was achieved in the response of the developed sensor.

Investigation of annealing effects on optical properties of Ti thin films deposited by RF magnetron sputtering

Titanium oxide thin films were synthesized through thermal oxidation of sputter deposited titanium layers on glass substrates. Transmittance spectra of UV–vis analysis were utilized to calculate thickness, refractive index and extinction coefficient of the oxidized layers by using Swanepoel method. Optical parameters like; optical band gap energy Egopt, conductivity σopt, dielectric constants ɛr, ɛi and dissipation factor tan(δ); were also determined. AFM imaging of the as sputtered thin films showed that with increasing deposition time, surface roughness increases. Optical measurements indicate that transmittance decreases with increasing sputtering time in visible and infrared spectral range.

Trapping-charging ability and electrical properties study of amorphous insulator by dielectric spectroscopy

Usually, the trapping phenomenon in insulating materials is studied by injecting charges using a Scanning Electron Microscope. In this work, we use the dielectric spectroscopy technique for showing a correlation between the dielectric properties and the trapping-charging ability of insulating materials. The evolution of the complex permittivity (real and imaginary parts) as a function of frequency and temperature reveals different types of relaxation according to the trapping ability of the material. We found that the space charge relaxation at low frequencies affects the real part of the complex permittivity ε′ and the dissipation factor Tan(δ). We prove that the evolution of the imaginary part of the complex permittivity against temperature ε″=f(T) reflects the phenomenon of charge trapping and detrapping as well as trapped charge evolution Qp(T). We also use the electric modulus formalism to better identify the space charge relaxation. The investigation of trapping or conductive nature of insulating materials was mainly made by studying the activation energy and conductivity. The conduction and trapping parameters are determined using the Correlated Barrier Hopping (CBH) model in order to confirm the relation between electrical properties and charge trapping ability.

Ferroelectric and Optical Properties of BST/BZT/BST Sandwich Structure Thin Films Prepared by RF Sputtering

In this work, (Ba0.65Sr0.35)TiO3 (BST) and Ba(Zr0.20Ti0.80)O3 (BZT) ceramic targets were prepared using the traditional solid-state reaction technique, which were sintered at 1200 °C for 2 h. The thin films of BST, BZT and sandwich structure BST/BZT/BST were grown on Pt/Ti/SiO2/Si(100) and Si(100) substrates by rf-sputtering at 500 °C, respectively. And all samples crystallied at temperatures 650 °C for 30 min in oxygen atmosphere. The cross-sectional images of the thin films were characterized by scanning electron microscope (SEM). The dielectric constant and dissipation factor tan of the BZT, BST and BST/BZT/BST thin films are 680 and 0.030, 240 and 0.021, 85 and 0.018, respectively at 100 kHz. Compared with BST and BZT films, the BST/BZT/BST film has lower dielectric constant and lower dissipation. The remanent polarization (Pr) of the sandwich structure BST/BZT/BST thin film is up to 9.57 μC/cm2, the Pr value is larger than that BST (0.25μC/cm2) film and BZT (8.45μC/cm2) film. The optical properties (refractive index n and extinction coefficient k) of the BST/BZT/BST film on Si(100) substrate were measured by n &amp; k analyzer 2000.

Studying the Effect of Sintering Temperature on the Electrical Properties for the System ZnxNi1-x-yCuyFe2O4

By The Conventional Solid State reaction is used to prepared the (ZnFe2O4, NiFe2O4,CuFe2O4) From the Oxide of (Cu, Zn, Ni & ferrous oxalate) while had emphasized the Crystallize Synthesis accurately and Sort by these Synthesis by using the Technique (X.R.D), it is mixedtoFormedthe final Synthesis (Ni1-x-yZnxCuy Fe2O4) with (x= 0.2,0.4,0.6, 0.8) &(y=0.2,0)as pressed pellets are sintered at (1200,1250,1300)C for (2h) after every once sintered bulks densities and electrical characteristic are measured. The electrical characteristics for these samples, included the measure of D.C current as electrical resistivity () and A.C current as the measure of dielectric constant (),and dissipation factor (tan).

High-rate sputtering of thick PZT thin films for MEMS

Crack and void free polycrystalline Lead Zirconate Titanate (PZT) thin films in the range of 5 µm to 10 µm have been successfully deposited on silicon substrates using a novel high rate sputtering process. The sputtered PZT layers show a high dielectric constant er between 1,000 and 1,800 with a moderate dissipation factor tan (δ) = 0,002 − 0,01 measured at f = 1 kHz, a distinct ferroelectric hysteresis loop with a remanent polarisation of 17 µC/cm2 and coercive field strength of 5.4 kV/mm. The piezoelectric coefficients d33,f = 80 pm/V are measured by using a Double Beam Laser Interferometer (DBLI). Based on this deposition process a membrane actuator mainly consisting of a SOI layer and a sputtered PZT thin film was prepared. The deflection of this membrane actuator depending on the driving voltage was measured with a white light interferometer and compared to the results of finite element analysis (FEA). With this approach a transverse piezoelectric coefficient of about e31 = −11.2 C/m2 was calculated, whereas all the other material parameters in the model were lent from PZT-5A.