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Dielectric constant measurement of low loss liquids using stacked multi ring resonator
摘要： The concept of dielectric constant measurement has been extended and applied in agriculture, pharmaceutical and food industry for quality control of liquids. Dielectric analysis of material at microwave frequencies can be done using novel shielded stacked multi-ring resonator (SMRR). The dielectric constant of liquids and paste has been calculated using SMRR with greater accuracy than the planar resonator, boxed resonator and stacked resonator. SMRR contains a ring resonator with fed patch and parasitic patch with different numbers and sizes of rings. The dimensions of rings on the parasitic patch are optimized to achieve Quality factor Q greater than 100 and return loss less than -2 dB. Due to dual resonance in novel SMRR, structure losses are reduced by 50% than planar resonator structure. The behavior of SMRR structure at the 2.45 GHz frequency is studied with E ?eld and H ?eld. 3D model is designed in Computer Simulation Technology Microwave Studio (CST MWS) using TLM (Transmission Line Modeling) solver. Electromagnetic ?eld analysis as well as impedance bandwidth of SMRR using CST MWS 3D model prove that electromagnetic coupling in SMRR structure increases thus improves quality factor. In SMRR quality factor increases and losses reduce help us to predict the complex permittivity of material for quality analysis.
关键词： quality factor,dielectric constant,return loss,Stacked multi ring resonator
更新于2025-09-10 09:29:36
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Physical properties of Cd-doped ZnS thin films
摘要： In this research, un- and Cd-doped ZnS nanostructures were synthesized using an electrodeposition method. The electrolyte contained 20 mM ZnCl2, 20 mM Na2S2O3 and the various amounts of CdCl2 solution. The X-ray diffraction (XRD) patterns of the as-deposited samples exhibited that Cd doping lead to decrease the crystallite size (D) of ZnS meanwhile the lattice strain, lattice stress, dislocation density (γ), and stacking fault energy (SF) were increased. Field emission scanning electron microscopy (FESEM) images depicted very fine equiaxed grains (20 to 50 nm), in addition to big grains (200 to 400 nm) with the preferential orientation. The reflectance spectra of ZnS thin films indicated a decrease in the reflectance peaks and refractive index (n), after Cd doping. Based on the transmission spectra, the un- and Cd-doped ZnS samples showed an absorption edge between 328 – 357 nm. The band gap energy for undoped ZnS sample was estimated as 3.95 eV, which it was reduced to 3.63 eV for the Cd-doped ZnS samples owing to the presence of imperfections and crystalline disorder in the Cd-doped samples. Furthermore, the obtained dielectric constant of the Cd-doped ZnS thin films was smaller than undoped ZnS sample, which means that the Cd-doped ZnS samples were more appropriate than the undoped ZnS sample for application in the fast photodetectors. The photoluminescence (PL) spectra of the undoped ZnS thin film was presented six emission peaks at 340, 413, 536, 574, 748, and 878 nm as an outcome of near band emission (NBE) and crystalline defects such as zinc interstitials (IZn), zinc vacancies (VZn), sulfur interstitials (IS), ZnS self-defect, and the defect states between the valence band (VB) and the conduction band (CB) of ZnS. Moreover, the PL emission of the Cd-doped ZnS samples demonstrated a red-shift relative to the undoped sample, which verified the UV-vis spectroscopy results.
关键词： nanostructures,electrodeposition,wide band gap,dielectric constant,Cd-doped ZnS
更新于2025-09-10 09:29:36
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Poly(vinylidene fluoride)/Plasma-Treated BaTiO3 Nanocomposites with Enhanced Electroactive Phase
摘要： Functional C=O and C-O groups are successfully fixated onto the surface of a high dielectric constant material barium titanate (BaTiO3) via non-thermal plasma. The strong dipole interaction exists between these functional groups and CH2 or CF2 groups of poly(vinylidene fluoride) (PVDF), resulting in the enhancement of the electroactive γ-phase of PVDF/BaTiO3 nanocomposites on one hand; on the other hand the dispersion of BaTiO3 is enhanced in the PVDF matrix, where the smaller spherulite size and better hydrophilic property are observed in the PVDF/plasma-treated BaTiO3 nanocomposite, comparing with the untreated ones. Therefore, the PVDF/plasma-treated BaTiO3 nanoparticles exhibited higher dielectric constant and lower dielectric loss than the PVDF/BaTiO3 nanoparticles.
关键词： plasma-treated barium titanate nanocomposites,dielectric constant,electroactive γ-phase,dielectric loss,poly(vinylidene fluoride) (PVDF)
更新于2025-09-09 09:28:46
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Electronic transport properties of (Se80Te20)100?xZnx (2?≤?x?≤?6) chalcogenide alloys
摘要： The bulk chalcogenide (Se80Te20)100-xZnx (2≤x≤6) alloys are prepared using melt quenching technique and electronic transport properties are studied in the frequency range 50 Hz–500 KHz and temperature range 400-520 K. The sharp peaks observed in X-ray diffraction pattern indicate the polycrystalline nature of prepared compositions. The measured dielectric properties and a.c. conductivity reveal the significant influence of Zn doping on the properties of the Se-Te matrix. The a.c. conductivity obeys Jonscher power law as ~ w s (s<1). To describe the conduction mechanism, the experimental results are analyzed in the framework of various theoretical models. The correlated barrier hopping (CBH) model successfully describe the observed frequency, temperature and composition response of ac conductivity.
关键词： a.c. conductivity,electronic transport properties,Chalcogenide alloys,dielectric constant,dielectric loss,X-Ray diffraction
更新于2025-09-09 09:28:46
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Investigation on Physical Properties of Semiorganic Nonlinear Optical Glycine Zinc Sulfate Single Crystal
摘要： Nonlinear optical single crystals of Glycine Zinc Sulfate (GZS) were grown by slow evaporation technique. Single crystal X-ray diffraction analysis revealed the crystal system and lattice parameter values. Powder X-ray diffraction analyses have been carried out and the diffraction patterns have been indexed. The optical properties of the crystals were determined using UV-Visible spectroscopy. Optical constants such as band gap, refractive index, extinction coefficient and electric susceptibility were determined from UV-Visible spectroscopy. The refractive index was determined using Brewster’s angle method. Hardness of the GZS crystal was estimated by Vicker’s hardness studies. Second Harmonic Generation (SHG) of GZS crystal was investigated by Kurtz powder technique. The dielectric constant and dielectric loss measurements were carried out for different temperatures and frequencies. The photoconductivity studies confirm that the grown crystal has negative photoconductivity nature. In order to investigate the growth mechanism and surface features, etching studies are carried out for the crystal.
关键词： NLO,single X-ray diffraction,SHG,UV-Vis-NIR spectrophotometer,dielectric loss studies,dielectric constant
更新于2025-09-09 09:28:46
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[IEEE 2018 Conference on Emerging Devices and Smart Systems (ICEDSS) - Tiruchengode, India (2018.3.2-2018.3.3)] 2018 Conference on Emerging Devices and Smart Systems (ICEDSS) - Study the Complex Dielectric and Energy loss function of Graphene oxide nanostructures using linear optical constant
摘要： In this paper, the linear optical properties of Graphene oxide nanostructure have been calculated depending on the absorbance spectra at wavelength range (200-800 nm). The linear optical constants such as refractive index (n) and extraction coefficient (k) are calculated for analyzing the Complex dielectric function. The surface and volume vitality energy loss has been studied by the dielectric measurement.Present speculative concepts were used to discuss the attained results.
关键词： Loss Function,Refractive Index,Dielectric Constant
更新于2025-09-09 09:28:46
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[IEEE 2018 3rd International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT) - Bento Gon?alves, Brazil (2018.8.27-2018.8.31)] 2018 3rd International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT) - Using Metamaterial Complementary Split-Ring Resonators for Measuring Dielectric Constants and Loss Tangents at 22 GHz
摘要： This paper presents a method using a metamaterial complementary split-ring resonator (CSRR) to measure the dielectric constant (Dk) and loss tangent (Df) of materials at a frequency of 22 GHz. The method involves calculating the permittivity of an unknown material based on the oscillation frequency changes of a CSRR, which is caused by the material under test. This method with a CSSR sensor uses only the resonance frequency and the S21 magnitude response at the resonance frequency to calculate Dk and Df. The measurement accuracy was assessed by comparing the results with the declared values specified in the datasheets of material manufacturers. The results show good agreement with the declared values in the datasheets. Thus, with this method, the dielectric properties of materials at high frequencies of millimeter waves (mm-waves) can be characterized and a non-destructive sensor can be built.
关键词： metamaterial,loss tangent,dielectric constant,CSRR
更新于2025-09-09 09:28:46
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Role of reduced graphene oxide in dielectric enhancement of ferroelectric polymers composites
摘要： Flexible polymer composites with high dielectric constant are highly desirable for electrical and electronic applications. This work demonstrated the preparation of high-dielectric-constant (high-k) and low-dielectric-loss flexible composites by incorporating reduced graphene oxide (rGO) and the colossal-dielectric-constant CaCu3Ti4O12 (CCTO) particles in poly(vinylidene fluoride) matrix via solution processing. The three-phase composites combine the merits of each two-phase composite while avoiding the demerits of the two-phase composites. A high dielectric constant (～40.4) and relatively low dielectric loss tangent (～0.08) at 1 kHz were achieved when rGO and functionalized CCTO were 0.61 vol% of 12.5 vol%, respectively. The enhanced dielectric properties of the composites may originate from both induced polarization effect and intrinsic high dielectric constant of rGO, and the tunneling effect between rGO sheets play an important role in electrical conductivity and dielectric loss of the composites. It is believed that the ceramic/rGO/polymer three-phase hybrid strategy can be used to design and fabricate high-k composites with desirable flexibility and dielectric applications.
关键词： poly(vinylidene fluoride),CaCu3Ti4O12,reduced graphene oxide,dielectric constant
更新于2025-09-09 09:28:46
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Extraordinary dielectric properties at heterojunctions of amorphous ferroelectrics
摘要： Materials having a high dielectric constant are needed for a variety of electrical applications from transistors to capacitors. Ferroelectric amorphous-oxide (glass) alkali-ion electrolytes of composition A2.99Ba0.005ClO (A = Li, Na) are shown by two different types of measurement and different consistent analysis to have extraordinarily high dielectric constants varying from 109 at 25°C to 1010 at 220°C if the glass is properly conditioned. These anomalously high dielectric properties coexist with alkali-ion conductivities at 25°C that are equivalent to those of the best organic-liquid electrolytes of a Li-ion cell, and cyclic voltammetry (CV) in a Au/glass electrolyte/Au cell is stable from ?10 to +10 V. A model to interpret microscopically all the key features of the CV curves shows that the electric-double-layer capacitors (EDLCs) that form at the gold/electrolyte interfaces in the Au/glass electrolyte/Au heterojunction reverse polarization at an applied voltage V = ± 2.1 V resulting in three almost equivalent discharging capacitances for a single physical capacitor from -10 to +10 V.
关键词： amorphous-oxide,ferroelectric,alkali-ion electrolytes,dielectric constant,electric-double-layer capacitors,cyclic voltammetry
更新于2025-09-09 09:28:46
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Temperature and frequency effect on the electrical properties of bulk nickel phthalocyanine octacarboxylic acid (Ni-Pc(COOH)8)
摘要： The AC conductivity of nickel phthalocyanine octacarboxylic acid was investigated from 100 Hz to 1 MHz and temperature from 290 to 423 K. The AC conductivity was found to vary with frequency (σ(f)) and form two dispersion regions; the associated exponent factor “s” values were found to vary from 1.17 to 1.34 and from 0.42 to 0.67 (< 1). The value and temperature dependent of s are found in agreement with conduction mechanism models of large-polaron tunneling and the correlated barrier hopping, at the first and the second regions, respectively. The real and the imaginary parts of the dielectric constant were observed to decrease as the frequency increases indicating the pronounce contribution of low-frequency polarization mechanisms. Furthermore, the activation free energy ?F, enthalpy ?H, and entropy ?S of the sample were calculated as well.
关键词： enthalpy,polarization mechanisms,AC conductivity,activation free energy,dielectric constant,nickel phthalocyanine octacarboxylic acid,entropy
更新于2025-09-09 09:28:46