Abstract—An electrodeless measurement technique of complexdielectricpermittivity of high-K dielectric ﬁlms is described. The technique is based on a quasi-optic Fabry-Perot resonator and modiﬁed for investigation of two-layer dielectric structures — substrate/K-ﬁlm. This procedure is destined to be used for providing a simple intermediate control of parameters of high-K ﬁlms before the following technological process. Regimes of measurements providing the most sensitive conditions for deﬁnition of ﬁlm parameters are considered. The proposed method is tested on two-layer structures with well- known parameters and is used for characterization of ferroelectric (Ba,Sr)TiO 3 ﬁlms in the millimeter
As a result of measurements of complexdielectricpermittivity of powders of quartz granules with diﬀerent sizes, it is shown that in the sandy rocks saturated with water at values of saturation level between 0.6 and 0.9 (irrespective of the total pore volume), the relaxation phenomena which are assumedly caused by interfacial polarization on the water-air border can be observed. Wherein in the band of a relaxation, the real part of CDP of gradually saturated rocks is higher, and speciﬁc equivalent conductivity is signiﬁcantly lower than in completely saturated rocks and rocks while drying. The result shows considerable reduction of attenuation in gradually saturated rocks that allows reaching a bigger sensing depth at a georadar-location in such cases.
Abstract. The seasonal evolution of sea-ice microstructure controls key ice properties, including those governing ocean– atmosphere heat and gas exchange, remote-sensing signa- tures, and the role of the ice cover as a habitat. Non- destructive in situ monitoring of sea-ice microstructure is of value for sea-ice research and operations but remains elu- sive to date. We examine the potential for the electric prop- erties of sea ice, which is highly sensitive to the brine dis- tribution within the ice, to serve as a proxy for microstruc- ture and, hence, other ice transport properties. Throughout spring of 2013 and 2014, we measured complexdielectricpermittivity in the range of 10 to 95 kHz in landfast ice off the coast of Barrow (Utqia˙gvik), Alaska. Temperature and salinity measurements and ice samples provide data to char- acterize ice microstructure in relation to these permittivity measurements. The results reveal a significant correlation between complexdielectricpermittivity, brine volume frac- tion, and microstructural characteristics including pore vol- ume and connectivity, derived from X-ray microtomography of core samples. The influence of temperature and salinity variations as well as the relationships between ice proper- ties, microstructural characteristics, and dielectric behavior emerge from multivariate analysis of the combined data set. Our findings suggest some promise for low-frequency per- mittivity measurements to track seasonal evolution of a com- bination of mean pore volume, fractional connectivity, and pore surface area-to-volume ratio, which in turn may serve as proxies for key sea-ice transport properties.
Quantum mechanism of interlayer polarization in condensed mediums in alternating electric field in the limits of low and extra-low temperatures is studied. Unbalanced density matrix is calculated for the ensemble of noninteracting protons, moving in one-dimension multipit potential image of rectangular shape in variable polarizing field. With the help of unbalanced density matrix, anomalous effects are studied, connected with the move of low-temperature maximum loss tangent of dielectric in lamellar crystals towards the temperatures of liquid helium. Results of quantum- mechanical calculation of spectra of complexdielectricpermittivity (SCDP) may be used in the study of tunnel mechanism of spontaneous polarization of ferrielectrics (KDP, DKDP).
The regression equations and regression coefficients are as shown in the above table. The obtained complexdielectricpermittivity value were correlated with the physical properties of the agricultural soil under study. Least square fitting technique was used to draw a line and cover maximum points through the line. The regression equation and the regression coefficient is as shown in the table above.
6. Ajay Chaudhari, Anita Das, Garigipati Raju, Harish Chaudhari, Prakash Khirade, Navinkumar Narain, and Suresh Mehrotra: Complexpermittivity spectra of binary mixture of ethanol with nitrobenzene and nitro toluene using time domain technique. Proceedings of the National Science Council, Republic of China, Part A 2001; 25(4):205-210. 7. Hosamani MT, Fattepur RH, Dhasepande DK, and Mehrotra
like the effective plasma frequency for periodic arrays of very thin metal wires . Although the differences between models (4) and (5) have been analyzed in-depth [6, 8], up to now there are no simple analytic expressions for the permittivity components, which can predict both results as well as the crossover between them. In principle, the two regimes could be described within the effective medium approach proposed by Rytov . However, the calculation of the effective permittivity would require the numerical solution of the exact dispersion equation, especially in the case of electromagnetic modes propagating along the z axis  and having a low-frequency gap in their photonic band structure.
There are no literature data about the dielectric and microwave properties of nanocomposites comprising a higher amount of graphene nanoparticles (GNP), e.g. over 1 phr. Neither there are available reports on investi- gations on those properties carried out in a wider fre- quency range, first of all at frequencies lower than 8 GHz. Therefore the aim of this work is to study the influence that graphene nanoparticles (in amounts of 2 to 10 phr) have on the dielectric (dielectricpermittivity, dielectric loss angle tangent) as well as on the microwave proper- ties (absorption and reflection of the electromagnetic waves, the effectiveness of the electromagnetic shielding) of natural rubber based composites in a significantly
From the plots in Figure 8 one can determine that the highest reflective shielding effectiveness comes as a consequence of the reflection from the surface of the sample - the tested sample is Norit. For the other two tested samples the values of SER are very close to each other within the entire frequency range. On Figure 8 it is seen that within the range from 1 GHz up to 11 GHz the Norit sample displays the greatest absorption. At frequencies higher than 11 GHz the AG-K material possesses higher values of SEA, showing a different behavior in regard to the other two materials and determining the behavior of the total shielding effectiveness. For all studied materials the reflective and absorptive shielding effectiveness manifest resonance behavior at frequencies from 6 GHz to 12 GHz, whereupon at frequency 6 GHz the SEA is prevailing, while within the range from 7 GHz to 11 GHz, the reflecting component (SER) is prevailing in the total shielding effectiveness. The study of the electromagnetic properties of an ensemble of filler particles embedded in a polymer matrix requires the determination of not only the intrinsic electromagnetic properties of the individual filler particles but also the type and strength of inter- particle interactions, e.g., long-range dipole interactions, clustering, and matrix-particle interactions, such as multicontact chain adsorption to the surface of the filler. It has been well established that spatial in homogeneities, i.e., clusters of filler particles, give rise to polarization phenomena and therefore to a frequency dependence of the effective permittivity .
In this paper, a method for estimating the dielectricpermittivity of planar substrates has been presented. It is based on the use of a PSO- based optimization strategy and it only requires the photolitographic building of one-port MUT samples as well as simple input impedance measurements. For the experimental validation, two different planar substrates of different materials have been considered and the reconstruction results confirmed the reliability and effectiveness of the proposed approach.
Figure 5 shows the backscattered efficiencies which have been plotted against the size parameter ‘ka’. It can be seen from the graph that the backscattered ef- ficiencies in case of dielectric sphere is almost zero as compared to the CCM sphere. These are the most pronounced and interesting results that can be used in different applications. Taking different values of complex relative permittivity and permeability, we get the same results like in above.
Figure 2(c) compares weighting factors obtained with the three diﬀerent algorithms. It could be seen that, ﬁrstly, the two weighting factors obtained with the proposed method are quite diﬀerent, while those obtained with the Kato and Baker-Jarvis methods are in between these two weighting factors. Secondly, the weighting factor obtained with the Baker-Jarvis method is very close to β im , and this is also reﬂected in the fact that the uncertainties in the imaginary part of the permittivity obtained with both the Baker-Jarvis and the proposed method are close to each other. Since with the proposed method, two weighting factors have been used to calculate the real and imaginary parts of the complexpermittivity, respectively, the uncertainties in both parts of the results may be simultaneously the lowest.
determined by contacts between Al nano-particles. At the boundaries of clusters in the alternating electric field an accumulation and redistribution of free charges occurs, which changes the initial internal electric field. It is known that at low frequencies, internal electric fields are distributed accordingly conductivity and high frequen- cies—respectively the dielectricpermittivity. Therefore, the decrease ε '' and tg δ with increasing content of alu- minum nano-particles can be explained by the appearance of a relatively strong internal field in semiconductors and nano-clusters.
Alumina is the ceramic form of sapphire. It has balanced properties of insulation, thermal conductivity and breaking strength. It is usually available in white color having dielectric constant varying from 9.5 to 10 with loss tangent tanδ = 0.0002. Its unique property is surface roughness and excellent adhesion with a thin film and thick film metallization due to fine particles. Various advantages of Alumina are: Physical and chemical properties are stable even at very high temperatures, High Mechanical strength, Good in insulation properties, Less porous with good smoothness. Gold metallization is frequently used with alumina. Usually a very thin adhesion layer is used between alumina and gold.
The samples were subsequently calcined at various temperatures from 600°C to 900°C for 8 hours. The progress of the reaction was followed with the help of an X-ray diffractometer (XRD) with CuKα (λ=1.5405Å) radiation. For dielectric measurements, the powder samples were pressed into pellets with a uniaxial pressure of 8 tons/cm 2 , and then sintered at 1100°C for 8 h, with a heating rate of 5°C/min. The microstructure of the ceramics was examined by scanning electron microscopy (SEM) (Quanta 200 FEI model EDAX).
Hertzian potentials have been used to solve different electromagnetic problems: in the study of the properties of aperture array systems , non-linear waveguides , Green’s functions for multilayered media  and electromagnetic wave interaction with nanodevices . They have also been applied for the determination of TE and TM modes of circular cylindrical cavities using magnetic-type and electric-type Hertzian potentials res- pectively . Figure 1 shows the case of a cylindrical dielectric resonator enclosed by a metal shield, where b is the radius of the outer cylinder, a is the inner resonator radius and d is the height (length of the structure). The configuration can be regarded as a cylindrical waveguide enclosing a central sample of radius a, and terminated by perfectly conducting planes. The general solution for the axial E field in TM modes was discussed in , proposing a general solution for the axial E field for TM modes.
In order to estimate the uncertainty in the complexpermittivity measurements obtained by shielded dielectric resonator technique, we begin by analyzing the measurement process according to the formulation discussed in Section 2. Starting from a set of nominal specifications such as the characteristics of a given dielectric for the sample under test, cavity dimensions (designed to resonate approximately at a desired frequency for the selected mode), and conductivity of the metal enclosure; the nominal direct measurement results are calculated theoretically, as shown in Figure 2.
As expected from Mie theory, the dielectric sphere is equivalent to a magnetic dipole near the magnetic resonance mode and the magnetic field is mainly localized in the sphere as shown in Figure 4(a). However, when the CTO rods are placed beside the dielectric sphere, the magnetic field distribution is changed. The magnetic field in the gap enhances greatly while that in the sphere decreases as the rod approaches the dielectric sphere. When the distance between the rod and the sphere is reduced to zero, the intensity of the magnetic resonance even decreases by about 15% from about 5.7×10 4 A/m to
microwave heating. The results show that when the water is heated under high microwave power, speeding up the stir can improve the uniform of temperature. But if the rotate speed is fast enough, going on speeding up the stir cannot decrease the temperature difference any more. With large value of the imaginary part of relative complexpermittivity, the temperature difference is obvious even though the rotate speed is fast enough. Maybe it is because that with high microwave power or large value of the imaginary part of relative complexpermittivity, the speed of heating in the water is too fast. And on the interface of the water and air, the velocity of fluid flow is nearly equal to zero, so the thermal convection is weak and speeding up the stir cannot eliminate the situation that part of the water is heated too fast. Increasing the dynamic viscosity, the temperature difference in the water which is heated by microwave rises. When the value of dynamic viscosity is very large, the temperature difference is obvious even though the rotate speed is fast enough. Maybe the reason is that the heat transfer is weak because of slow speed of fluid convection with large value of dynamic viscosity. The coupled simulation of electromagnetic field, fluid field and thermal field provides a more accurate and effective method to simulate the heating process of chemical reactions under microwave, which makes it possible to further study the mechanisms of the special effects and non-thermal effects in microwave heating.