Sintering and Electrical Properties of Tungsten Doped Pb(Zr0.95Ti0.05)O3 Ferroelectric Ceramics

2011 ◽  
Vol 687 ◽  
pp. 380-384
Author(s):  
Jun Xia Wang ◽  
Xu Lan Zhen ◽  
Shi Yuan Yang ◽  
Jin Wang ◽  
Ke Tang
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Relative Dielectric Constant ◽  
Pulsed Power ◽  
Ferroelectric Ceramics ◽  
Ferroelectric Hysteresis Loop ◽  
Power Devices ◽  
Maximum Value ◽  
Ferroelectric Hysteresis

The effect of WO3 additions on the sintering ability and electrical properties of Pb(Zr0.95Ti0.05)O3 ferroelectric ceramics (PZT 95/5) was investigated. Pure and W-doped PZT 95/5 ceramics were prepared by the usual ceramic technique from raw oxides. The bulk density, microstructure, electrical properties of ceramics as a function of WO3 content were characterized. The results showed that the WO3 addition was benefit for the sintering densification of PZT, and the ceramics with 2.0 mol% WO3 addition exhibited the maximum value for the density (7.8 g/cm3) at a sintering temperature of 1250 °C. Moreover, piezoelectric constant (d33), relative dielectric constant (εr), dielectric loss (tanδ) and ferroelectric hysteresis loop of PZT 95/5 ceramics at the sintering temperature of 1250 °C all altered regularly with the change of WO3 doping level, whose optimum values were all obtained by doping 2.0 mol% WO3. The best values obtained for these parameters were: d33 = 65 pC/N, εr =314, tanδ = 0.028, Pr = 24.80 µC/cm2 and Ec = 1890 V/mm, respectively. These results show that tungsten doped Pb(Zr0.95Ti0.05)O3 ferroelectric ceramics can be hopefully used for the pulsed power devices.

EFFECT OF PROCESSING CONDITIONS ON ELECTRICAL PROPERTIES OF CaCu3Ti4O12 CERAMICS

2010 ◽  
Vol 24 (12) ◽  
pp. 1267-1273 ◽  
Author(s):  
RAMAN KASHYAP ◽  
TANUJ DHAWAN ◽  
PRIKSHIT GAUTAM ◽  
O. P. THAKUR ◽  
N. C. MEHRA ◽  
...  
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Nonlinear Behavior ◽  
Ferroelectric Hysteresis Loop ◽  
Processing Conditions ◽  
Reaction Route ◽  
Sintering Time ◽  
Maximum Value ◽  
Solid State Reaction Route ◽  
Ferroelectric Hysteresis

CaCu 3 Ti 4 O 12 ( CCTO ) ceramics were prepared by the solid-state reaction route. Effect of sintering time was studied on the polarization (P) versus electric field (E) behavior. Unlike conventional ferroelectric hysteresis loop, PE hysteresis behavior in CCTO ceramics was observed to exhibit ferroelectric-like loop where polarization does not saturate but gives a maximum value. Remnant polarization and maximum polarization was observed to increase with sintering time. Current (I)–voltage (V) characteristics shows a nonlinear behavior making them useful for varistor applications. Coefficient of non-linearity (α) is also found to depend on sintering duration.

Effects of Sintering Temperature on Microstructure and Properties in TiO2 Varistor Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 324-328 ◽  
Author(s):  
Ji Kang Yan ◽  
Guo You Gan ◽  
Jing Hong Du ◽  
Jia Lin Sun
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Solid Solubility ◽  
Sintering Temperature ◽  
Relative Dielectric Constant ◽  
Chemical Compositions ◽  
Barrier Structure ◽  
Tio2 Sample ◽  
Linear Coefficient ◽  
Microstructure And Properties

The effects of sintering temperature on microstructure, micro-composition, barrier structure and electrical properties of TiO2 varistors ceramics were investigated. The microstructures and chemical compositions of grains in TiO2 ceramics were measured by SEM and EDS. Based on the thermo electronic emission theory, Grain boundaries barrier structure was calculated by analyzing electrical properties of samples. The sample sintered at 1350°C exhibits better microstructure and properties. The grains size of the TiO2 sample sintered at 1350°C is about 15m, and other electrical properties are as follows: solid solubility of donor doping Nb5+ cation solute in TiO2 grains of 1.49mol%, barriers height of 0.28ev, barriers width of 48nm, varistor voltages of 5.25V/mm, non-linear coefficient of 4.2 and relative dielectric constant of 1.1×104.

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

Synthesis, Characterization and Electrical Properties of Barium Titanate Films Fabricated by Hydrothermal Method

2008 ◽  
Vol 368-372 ◽  
pp. 47-49
Author(s):  
Jian Ling Zhao ◽  
Xiao Hui Wang ◽  
Long Tu Li ◽  
Xi Xin Wang ◽  
Yang Xian Li
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Barium Titanate ◽  
Loss Tangent ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Hydrothermal Conditions ◽  
Batio3 Film ◽  
Maximum Value ◽  
Dielectric Constant And Loss

BaTiO3 films with a thickness up to 3 μm were fabricated under the hydrothermal conditions. It was found that the crystallinity of BaTiO3 increases with the concentration of Ba(OH)2 solutions. Along with the increasing of time, the crystallinity of BaTiO3 increases, reaches the maximum value and then decreases. The measured values of remanent polarization (Pr) and coercive field (Ec) are 1.74μC/cm2 and 24KV/cm. The leakage of the films at 1V is 10-7A/cm2. The dielectric constant and loss tangent of hydrothermal derived BaTiO3 film at a frequency of 1 KHz were 600 and 0.2, respectively.

Influence of Sintering Temperature on KNN-BF-LS Piezoelectric Ceramic

2016 ◽  
Vol 859 ◽  
pp. 8-12 ◽  
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Yu Zhang ◽  
Wen Xin Ma ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Loss ◽  
Piezoelectric Ceramic ◽  
Electromechanical Coupling ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Electromechanical Coupling Coefficient ◽  
Structure And Properties ◽  
Maximum Value

In this paper, (K0.5Na0.53)0.932Nb0.932O3-0.008BF-0.06LS (abbreviated as KNN-BF-LS) piezoelectric ceramic was prepared by sol-gel method. Structure and properties of ceramics were analyzed.Through analysis of the results, when sintering temperature is 1080°C, ceramic has good perovskite structure. At this temperature, grain size is more uniform, and structure is the most dense. Piezoelectric constant d33, electromechanical coupling coefficient Kp, dielectric constant εr reached the maximum value, respectively, 113pC/N, 0.33, 591. Dielectric loss tanδ reached the minimum 0.11.

Electrical Properties of Modified BNT Based Lead-Free Ceramics

2016 ◽  
Vol 872 ◽  
pp. 87-91
Author(s):  
Supalak Manotham ◽  
Tawee Tunkasiri ◽  
Pharatree Jaita ◽  
Pichitchai Butnoi ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Free Ceramics

The properties of modified Bi0.5Na0.5TiO3 (BNT) based lead-free ceramics were investigated. The BNT-based ceramics were prepared by a solid-state mixed oxide method Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggested that all samples exhibited a perovskite structure without second phase. The value of dielectric constant increased with increasing in sintering temperature. Moreover, high sintering temperatures could improve ferroelectric properties of BNT base lead-free ceramics.

Nonlinear Electrical Properties of (Sc, Ta) Doped TiO2 Varistor Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 289-292 ◽  
Author(s):  
Wen Bin Su ◽  
Jin Feng Wang ◽  
Hong Cun Chen ◽  
Guo Zhong Zang ◽  
Peng Qi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Crystal Lattice ◽  
Nonlinear Coefficient ◽  
Relative Dielectric Constant ◽  
Donor Concentration ◽  
Varistor Ceramic ◽  
Electrical Field ◽  
Schottky Type ◽  
Zno Varistors

The nonlinear electrical properties of TiO2-based varistor doped with 0.25mol% Ta2O5 and different contents of Sc2O3 were investigated. It was found that the TiO2 varistor ceramic doped with 0.10mol% Sc2O3 exhibited an optimal nonlinear coefficient of 7.8, a breakdown electrical field of 16.0V/mm, and relative dielectric constant of 1.27 × 105 (measured at 1 kHz). In order to analyze the effect of Sc2O3 on TiO2 varistors, studies were made on the capacitance versus voltage characteristics. A Schottky-type barrier, which is assumed as the origin of varistor behavior, was inferred from the C-V measurement. The barrier height and donor concentration were obtained as 0.41eV and 1.21 × 1026cm-3, respectively, for sample doped with 0.10mol% Sc2O3. Analogized to the ZnO varistors, the formation mechanism of Schottky-type barrier was discussed in this paper by the theory of defect in crystal lattice.

scholarly journals Design of a 0.5–18 GHz Wideband Switching Matrix Box for Electronic Support Measurement

2020 ◽  
Vol 20 (4) ◽  
pp. 293-301
Author(s):  
Yuseok Jeon ◽  
Jaejin Koo
Keyword(s):  
Dielectric Constant ◽  
Noise Figure ◽  
Relative Dielectric Constant ◽  
Dielectric Substrate ◽  
Input Frequency ◽  
Dielectric Thickness ◽  
Maximum Value ◽  
The Matrix ◽  
Switching Matrix ◽  
High Band

In this paper, we design and fabricate a broadband switching matrix box with low-noise figure, flat gain characteristics, and reliability by applying the chip-and-wire process using a bare-type MMIC device. To compensate for the mismatch among many components, the limiter, switch, amplifier, and power divider, which are suitable for sub-band frequency characteristics, are designed and applied to the matrix box. The matrix box has three submodules that are phase-matched for each frequency band and one built-in test (BIT) submodule to select the BIT path for calibration. Phase-matched RF semi-rigid cables of different lengths are used to connect to the external interface of the matrix box. The main RF line is a dielectric substrate, RT/Duroid 5880, with a relative dielectric constant of 2.2 and a dielectric thickness of 0.127 mm. The BIT path is a dielectric substrate, ceramic alumina (AI<sub>2</sub>O<sub>3</sub>), which has a relative dielectric constant of 9.8 and a dielectric thickness of 0.254 mm. In the wideband switching matrix box, the gain is from −1.71 dB to −2.69 dB at LB (input frequency, 0.5−2 GHz), with a flatness of 1.0 dB. Th e gain is from +14.8 dB to +12.4 dB at MB (input frequency, 1−6 GHz), with a flatness of 2.4 dB. The gain is from +12.6 dB to +9.4 dB at HB (input frequency, 6−18 GHz), with a flatness of 3.2 dB. The measured values of the noise figure are 2.69 dB at low band, 4.4 dB at medium band, and 5.95 dB at high band with a maximum value. The measured value of phase matching at high band is 7º with a maximum value.

Effect of Sintering Temperature on Structure and Electric Properties of (Ba0.96Ca0.04)(Zr0.05Ti0.95)O3 Ceramics

2015 ◽  
Vol 655 ◽  
pp. 141-146
Author(s):  
Xin Guan ◽  
Xiang Yun Deng ◽  
Jian Hao ◽  
Guang Hao Sun ◽  
Chuang Jun Huang
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Calcium Titanate ◽  
Ferroelectric Ceramics ◽  
X Ray Diffraction ◽  
Pure Perovskite Structure ◽  
Maximum Dielectric Constant ◽  
Gel Technique

Barium calcium titanate (Ba0.96Ca0.04)(Zr0.05Ti0.95)O3 ferroelectric ceramics were prepared by sol–gel technique. The ceramics were sintering at 1290°C-1370°C. X-ray diffraction was employed to investigate the microstructure, and the surface topography was investigated by SEM graphs. The dielectric constant vs temperature was measured by Temperature dielectric spectrometer, and TF Analyzer 2000 measured the ferroelectric properties. It can be found that all the ceramics show pure perovskite structure suggesting that solid solution were formed. SEM showed that the samples uniform in grain size at 1330 °C. Our study revealed that when the sintering temperature is 1330 °C the maximum dielectric constant was 29,600, the maximum piezoelectric coefficient d33 could reach 399pm/V and the remanent polarization (Pr) was 8.3 μc/cm2, respectively.

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