共查询到20条相似文献,搜索用时 0 毫秒
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Hirofumi Kakemoto Song-Min Nam Satoshi Wada Takaaki Tsurumi 《Journal of Electroceramics》2006,16(4):561-564
A high frequency dielectric measurement method was proposed using a non-contact probe. The microwave reflection intensity
was measured for Al2O3 and SrTiO3 substrates at room temperature as a function of distance between sample and probe. The difference of reflection intensity
for Al2O3 and SrTiO3 substrates was observed in the region where the distance of 0.2 mm between sample and probe, and it was caused from dielectric
permittivities of samples. The reflection coefficient of sample was estimated in comparison with results of electromagnetic
simulation. The reflection intensity for Al2O3 and SrTiO3 substrates was transformed to dielectric permittivity at reflection intensity minimum point. 相似文献
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In this study, the microwave dielectric and the acoustic properties of Pb(Zr
x
,Ti1-x
)O3 (PZT) thin films deposited using chemical solution deposition (CSD) were investigated using the same measurement setup. High
dielectric constants in the range of ~280–540 and loss tangents less than 0.1 at 4 GHz were measured, where the value depends
on the thickness of the PZT film. The voltage tunability of the 340 nm and 440 nm thick PZT thin films was ~34% and 5% for
the 140 nm thick PZT film at 120 kV/cm and 4 GHz. The acoustic parameters of the PZT thin films under DC bias voltages were
determined using a one-dimensional acoustic wave resonator model. For the PZT films of thicknesses 340 nm and 440 nm, the
acoustic resonance frequency shift was about 15 MHz and the electromechanical coupling coefficient was ~10% at an electric
field of 160 kV/cm. The large dielectric constant and high tunability suggest that the characterized PZT thin films may be
suitable for radio frequency (RF) applications such as high-density RF MIM capacitors and other tunable devices. 相似文献
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M. Sayer D. S. Mcintyre M. Sedlar A. Mansingh R. Tandon V. Chivukula 《Integrated ferroelectrics》2013,141(1-4):277-286
Abstract A technique is described for evaluating dielectric data on ferroelectric films using a Cole-Cole distribution function to separate film and electrode capacitance and resistance. The nature of the information obtained, and methods for validating the conclusions are discussed. The method is applied to lead zirconate titanate films on platinum and ruthenium oxide. Electrode capacitances are generally of the same order of magnitude as the film capacitance. 相似文献
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Reboul J.M. Cherifi A. Carin R. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2001,8(5):753-759
Space charge measurements form a recognized test for the characterization of insulating materials. The present paper is concerned with the determination of space charge in dielectric films for capacitors. We develop a new measuring technique inspired by thermal step method (TSM). Its originality is the use of an alternative thermal excitation so that the technique can be called alternative thermal wave method (ATWM). The equipment employed to generate alternative thermal excitations (sine or triangle) is described. The upper limit of the efficient frequency range is 10 Hz. Signal processing is made easier and more accurate because of the periodicity of the measured phenomena 相似文献
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Kuga Y. Lee S.-W. Taya M. Almajid A. Sangil Lee Jing-Feng Li Watanabe R. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2005,12(4):827-834
The conductor loading method has been used for creating a lossy dielectric material with a desired loss tangent. This method may also be applicable for developing high dielectric constant materials. In this paper, we will present the experimental results of the dielectric properties of BaTiO/sub 3/ and BaTiO/sub 3/ -platinum (BaTiO/sub 3/-Pt) composites. These composite materials were designed to increase the real part of the effective dielectric constant at high frequency. Three different platinum volume fractions were used, 3, 5 and 10%, to make BaTiO/sub 3/-Pt composites, in addition to a pure BaTiO/sub 3/ material. To characterize the BaTiO/sub 3/-Pt composites, microwave frequency measurements were conducted using the waveguide transmission technique. The experimental and numerical results verify that it is possible to increase the dielectric constant using the conductor loading method. 相似文献
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Qi X. Ronzello J.A. Boggs S. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2005,12(6):1235-1240
A capacitor formed of fluid-impregnated paper metalized on one side and a polymer film results in a relaxation peak caused by the much more rapid polarization of the dielectric fluid impregnated paper relative to the polymer film. This results in the capacitance being a function of frequency, with a substantial increase in capacitance at very low frequencies. A theory for such a capacitor is developed and compared with measurements on actual capacitors with relatively good agreement. The implications of the theory for discharge current and discharge efficiency are discussed. 相似文献
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This paper proposes a method of studying and modeling the dielectric absorption in capacitors. Because of dielectric absorption, the voltage on a charged capacitor partially recovers after momentarily shorting its terminals. The magnitude of this voltage recovery depends mainly on the dielectric material. Dielectric absorption causes errors in some analog applications based on charging and discharging of capacitors, such as sample-and-hold circuits, integrators and active filters. Designing compensation circuits based on models of the dielectric absorption can reduce these errors. This paper presents an analytical method to build a mathematical model of the dielectric absorption, and an equivalent electrical circuit. The method is based on compartmental analysis theory, mostly used in medicine and biology to study the kinetics of substances in biological systems 相似文献
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T. S. Kalkur Woo-Chul Yi Elliott Philofsky Lee Kammerdiner Tony Rywak 《Integrated ferroelectrics》2013,141(1-4):289-295
Abstract High dielectric constant Ba0.96Ca0.04Ti0.84Zr0.16O3 (BCTZ) thin films were deposited on Pt/Ti/SiO2/Si substrates by spin on metal-organic decomposition (MOD) technique. Undoped and 0.4% Mg-doped BCTZ thin films were annealed in the temperature range from 600 to 900 °C for 1 hour in oxygen environment. The crystal structure of BCTZ thin films was analyzed by X-ray diffraction. The electrical properties of BCTZ thin films were investigated by capacitance—voltage (C—V) characteristics. Also, the electrical properties of these films were compared in conjunction with 0.4% Mg doping effect of BCTZ thin films for possible high dielectric constant material applications. 相似文献
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Kyung Woong Park Young Ki Han Kiyoung Oh Doo Young Yang Chul Ju Hwang Jaehoo Park 《Integrated ferroelectrics》2013,141(1-4):45-52
Abstract Low temperature metal-organic chemical vapor deposition (MOCVD) process of Ru films for use as electrode material was studied using a noble dome type reactor, liquid delivery technique and a new precursor. The films were grown at temperatures ranging from 275°C to 480°C in which film growth was controlled by a surface chemical reaction with a small activation energy of 0.21 eV. The root-mean-squared surface roughness was as low as 23 Å for a film grown at 290°C on a SiO2 surface. 相似文献
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Michael Voigts Wolfgang Menesklou Ellen Ivers-Tiffee 《Integrated ferroelectrics》2013,141(1-4):383-392
Abstract Dielectric properties and tunability of Ba0.60Sr0.40TiO3 (BST) and BaZr0.25Ti0.75O3 (BZT) thick films and bulk ceramics have been investigated as a function of temperature (90 K - 320 K) in the kHz region. Thick films show compared to bulk ceramics low permittivity and a very broad ferroelectric phase transition which leads to low temperature dependence of tunability. Tunability of 30% can be achieved with an external field of 2 kV/mm. Measurements in the microwave region adumbrate that the dielectric losses of BZT are about three times higher than that of BST thick films. 相似文献
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Allen M. Hermann Badri Veeraraghavan Davor Balzar Fred R. Fickett 《Integrated ferroelectrics》2013,141(1-4):161-173
Abstract Oxide ferroelectric thin films for frequency-tunable microwave devices, in which the dielectric constant of the non-linear dielectric is varied by application of electric fields, have been deposited using PLD. We have fabricated single phase epitaxial Ba0.6Sr0.4TiO3 and KTaO3 thin film capacitors for applications at 300K and 77K, respectively. Single phase KTaO3 films were obtained only with excess potassium source in the target along with KTaO3 perovskite phase. The films have been characterized for structure and morphology by X-ray diffraction and AFM. The dielectric properties were measured in the low frequency range from 100 kHz to 10 MHz, using interdigitated capacitors. Low loss tangents (0.002 at 300K) were observed for highly oriented Ba0.6Sr0.4TiO3 films. The importance of low losses for various devices is discussed and the dielectric constants, loss tangents and tunability of these films are reported in this paper. 相似文献
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Johri G.K. Johri M. Sharma R. Johri S. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2003,10(1):96-101
A study of the dielectric response of dimethyl substituted pyridines (lutidines) has been reported in the temperature range 293-323 K. The microwave cavity spectrometer has been used to measure the relative shift, width and amplitude of the resonance profile for the sample loaded in the cavity operated in TM/sub 010/ mode at a fixed frequency of 9.0 GHz. The Slater's perturbation equations are used to analyze the measured data and permittivity and dielectric loss have been obtained using interaction form factor. Significant effect in the dielectric response and interaction has been found due to change of the position of the -CH/sub 3/ functional groups. 相似文献
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Abstract Bi2(Zn1/3Nb2/3)2O7, BiZN, materials possess high dielectric constant and low loss factor in microwave frequency region. They have good potential for device application, especially in the form of thin films. However, the microwave dielectric properties of a thin film are very difficult to be accurately measured. Evaluation on the dielectric behavior of the films through the performance of the microstrip line devices made of these films involves metallic conduction and stray field losses. A novel measuring technique, which can directly evaluate the microwave dielectric properties of a thin film is thus urgently needed. In this paper, BiZN thin films were grown on [100] MgO single crystal substrates using pulsed laser deposition process. The high-frequency dielectric properties of thus obtained thin films were determined using optical transmission spectroscopy (OTS). The [100] preferentially oriented films with pyrochlore structure can be obtained for the thin films deposited at 400–600°C substrate temperature under 0.1 mbar oxygen pressure. OTS measurements reveal that the index of refraction (n=1.95–2.35) and absorption coefficient (k=0.28x10?4-2.25 × 10?4 nm?1) of the films vary insignificantly with the crystallinity of the BiZN films. 相似文献
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Ming Li Fortin J. Kim J.Y. Fox G. Chu F. Davenport T. Toh-Ming Lu Xi-Cheng Zhang 《IEEE journal of selected topics in quantum electronics》2001,7(4):624-629
Goniometric time-domain spectroscopy (GTDS), employing an ultrashort electromagnetic (EM) pulse technique, has been developed for measuring the dielectric constant of thin films in a broad band of gigahertz to terahertz. An ultrafast optoelectronic system, including an emitter and a detector unit, is constructed with a &thetas;-2&thetas; goniometer. A silicon wafer was analyzed as the reference substrate material. A sharp π phase-shift of the reflected EM wave was observed at the Brewster angle of 73.5° for a bare silicon wafer. The phase shift for a film on the Si substrate is relatively smooth due to its two surfaces' providing a complex reflectance. The dielectric constant of the film on Si, related with angular dependency of the phase shift, can be extracted by means of fitting the curve or measuring slope of the curve near the Brewster angle. The measured dielectric constants of FLARE, TiOx, and PZT film are reported 相似文献
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A. Kozyrev V. Keis O. Buslov A. Ivanov T. Samoilova O. Soldatenkov 《Integrated ferroelectrics》2013,141(1-4):427-436
Abstract This paper presents the experimental and modeling results on microwave (~37 GHz) investigations of SrTiO3 and (Ba,Sr)TiO3 ferroelectric films at high levels of microwave power. The ferroelectric film planar varactors were incorporated into the fin-line. The threshold microwave power leading to the appreciable variation in the microwave response of the tunable structure was determined. Thermal conditions of the varactors under test were analyzed. Thermal time constant and overheating of the ferroelectric films were estimated. The dependence of the varactor overheating on geometry was studied. Design optimization possibilities for the varactors in high microwave power applications are discussed. 相似文献